Q:

Front Cover for document part 3

This cover page is building from the solution posted in Front Cover or document part 2.   I am now trying to place a minipage and a logo with a blur shadow on the cover page like this:

Here is the code that is written so far:
\documentclass[11pt,letterpaper]{article}
\usepackage{libertine}
\usepackage{tikz}
\usetikzlibrary{backgrounds, calc, shadows, shadows.blur}

\usepackage{graphicx}

\pgfmathdeclarerandomlist{MyRandomColors}{%
    {red}%
    {red!25}%
    {magenta}%
    {magenta!25}%
    {olive}%
    {olive!25}%
    {brown}%
    {brown!10}%
    {violet}%
    {violet!25}%
    {gray}%
    {purple}%
    {yellow}%
    {orange}%
    {orange!25}%
    {cyan}%
    {green}%
}%

\definecolor{titlecolor1}{rgb}{.9,0.40,0.7}

\newcommand*{\GridSize}{20}

%#2-Gridsizex
%#3-Gridsizey
\newcommand*{\ColorCells}[2]{%
    \foreach \y in {1,...,#1} {
        \foreach \x in {1,...,#2} {
            \pgfmathrandomitem{\RandomColor}{MyRandomColors}
            \draw [draw=olive!45,fill=\RandomColor, fill opacity=0.2, ultra thick]
                ([shift={(\x-1,\y-1)}]current page.south west) rectangle ++(1cm,1cm);
        }%
    }%
}%

\listfiles
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[remember picture,overlay]
    \begin{scope}[scale=0.8,ultra thick,olive!45]
        \ColorCells{35}{27}
        \coordinate (input);
    \end{scope}

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{70}{70}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(.25,1)$)
{Depression Problems and Active Modeling};

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{20}{20}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(-5.5,21)$)
{(Spring 2016)};

\node[above right,
node font=\fontsize{40}{90}\selectfont\bfseries\sffamily,
text=titlecolor1!20!black] at ($(current page.south west)+(1,1)$)
{Jimmy Jones Jeremy};

%\tikzoverlay at (-4.37cm,3cm) {
%\begin{tikzpicture} \node [blur shadow]{
%        \includegraphics[scale=.15]{Logo}
%    };

\end{tikzpicture}

\begin{minipage}[l]{10cm}
Contributor: Dixie Wang\\
Date: February 15th, 2016\\
Filed: February 15th, 2016
\end{minipage}

\end{document}

I would like some help to get the cover to look like the attached image?   Thanks. 

A:

A regular node (with all positioning options) can be used for the logo, something like:
\node[blur shadow, anchor=north west] at 
     ($(current page.north west)+(1,-1)$) 
     {\includegraphics[width=5cm, height=4cm]{example-image}};

will do the work. 
And a similar solution can be applied for the minipage.  In fact you don't need a minipage to define a multiline node, just options like text width and align will help.  text width will automatically break lines, so in your case it's not needed because you break them with \\.
\node[blur shadow, text width=11cm, align=left, draw, anchor=south east,     
      fill=white] at ($(current page.south east)+(-6,5)$){ 
          Contributor: Dixie Wang\\
          Date: February 15th, 2016\\
          Filed: February 15th, 2016}; 

Complete code:
\documentclass[11pt,letterpaper]{article}
\usepackage{libertine}
\usepackage{tikz}
\usetikzlibrary{backgrounds, calc, shadows, shadows.blur}

\usepackage{graphicx}

\pgfmathdeclarerandomlist{MyRandomColors}{%
    {red}%
    {red!25}%
    {magenta}%
    {magenta!25}%
    {olive}%
    {olive!25}%
    {brown}%
    {brown!10}%
    {violet}%
    {violet!25}%
    {gray}%
    {purple}%
    {yellow}%
    {orange}%
    {orange!25}%
    {cyan}%
    {green}%
}%

\definecolor{titlecolor1}{rgb}{.9,0.40,0.7}

\newcommand*{\GridSize}{20}

%#2-Gridsizex
%#3-Gridsizey
\newcommand*{\ColorCells}[2]{%
    \foreach \y in {1,...,#1} {
        \foreach \x in {1,...,#2} {
            \pgfmathrandomitem{\RandomColor}{MyRandomColors}
            \draw [draw=olive!45,fill=\RandomColor, fill opacity=0.2, ultra thick]
                ([shift={(\x-1,\y-1)}]current page.south west) rectangle ++(1cm,1cm);
        }%
    }%
}%

\listfiles
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[remember picture,overlay]

\begin{scope}[scale=0.8,ultra thick,olive!45]
    \ColorCells{35}{27}
\end{scope}

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{70}{70}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(.25,1)$)
{Depression Problems and Active Modeling};

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{20}{20}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(-5.5,21)$)
{(Spring 2016)};

\node[above right,
node font=\fontsize{40}{90}\selectfont\bfseries\sffamily,
text=titlecolor1!20!black] at ($(current page.south west)+(1,1)$)
{Jimmy Jones Jeremy};

\node[blur shadow, anchor=north west] at ($(current page.north west)+(1,-1)$) {\includegraphics[width=5cm, height=4cm]{example-image}};

\node[blur shadow, text width=10cm, align=left, draw, anchor=south east, fill=white] at ($(current page.south east)+(-6,5)$){ 
Contributor: Dixie Wang\\
Date: February 15th, 2016\\
Filed: February 15th, 2016};

\end{tikzpicture}

\end{document}

Update: Colored "minipage"
Although it was not explicitly asked I've tried to mimic the squared, colorful and shadowed aspect of the so called minipage.  The best solution I've found was to add some more parameters to \ColorCells command and use an empty but shadowed node which will be covered for colored cells and text later on. 

\Colorcells has now five parameters, a coordinate for bottom left corner, its horizontal and vertical size (square number), a color list and fill opacity:
%#1-Origin: bottom left corner
%#2-Gridsizex
%#3-Gridsizey
%#4-ColorList
%#5-Opacity
\newcommand*{\ColorCells}[5]{%
    \foreach \y in {1,...,#3} {
        \foreach \x in {1,...,#2} {
            \pgfmathrandomitem{\RandomColor}{#4}
            \draw [draw=olive!45,fill=\RandomColor, fill opacity=#5, ultra thick]
                ([shift={(\x-1,\y-1)}]#1) rectangle ++(1cm,1cm);
        }%
    }%
}%

Now full page background and colored minipage are drawn with commands:
\begin{scope}[scale=0.8,ultra thick,olive!45]
    \ColorCells{current page.south west}{27}{35}{MyRandomColors}{0.2}
    \node[blur shadow, fit={($(current page.south west)+(9.2,5.2)$) 
         ($(current page.south west)+(20.2,9.2)$)}, inner sep=0pt] (fitaux) {};
    \coordinate (aux) at ($(current page.south west)+(9.2,5.2)$);
    \ColorCells{aux}{11}{4}{MyRandomColorsTwo}{1}
    \node[align=left, node font=\LARGE, text=white] at (fitaux.center) { 
          Contributor: Dixie Wang\\
          Date: February 15th, 2016\\
          Filed: February 15th, 2016}; 
\end{scope}

First ColorCells draws page background.  Next an empty node is drawn to add the shadow for the colored section which is drawn with second ColorCells command and finally, text is added with a regular node.  This minipage has been  missplaced from background grid to increase overlay effect. 
Complete code for second version:
\documentclass[11pt,letterpaper]{article}
\usepackage{libertine}
\usepackage{tikz}
\usetikzlibrary{calc, shadows, shadows.blur, fit}

\usepackage{graphicx}

\pgfmathdeclarerandomlist{MyRandomColors}{%
    {red}%
    {red!25}%
    {magenta}%
    {magenta!25}%
    {olive}%
    {olive!25}%
    {brown}%
    {brown!10}%
    {violet}%
    {violet!25}%
    {gray}%
    {purple}%
    {yellow}%
    {orange}%
    {orange!25}%
    {cyan}%
    {green}%
}%

\pgfmathdeclarerandomlist{MyRandomColorsTwo}{%
    {red!70!black}%
    {magenta!70!black}%
    {olive!70!black}%
    {brown!70!black}%
    {violet!70!black}%
}%

\definecolor{titlecolor1}{rgb}{.9,0.40,0.7}

\newcommand*{\GridSize}{20}

%#1-Origin
%#2-Gridsizex
%#3-Gridsizey
%#4-ColorList
%#5-Opacity
\newcommand*{\ColorCells}[5]{%
    \foreach \y in {1,...,#3} {
        \foreach \x in {1,...,#2} {
            \pgfmathrandomitem{\RandomColor}{#4}
            \draw [draw=olive!45,fill=\RandomColor, fill opacity=#5, ultra thick]
                ([shift={(\x-1,\y-1)}]#1) rectangle ++(1cm,1cm);
        }%
    }%
}%

\listfiles
\begin{document}
\pagestyle{empty}
\begin{tikzpicture}[remember picture,overlay
]

\begin{scope}[scale=0.8,ultra thick,olive!45]
    \ColorCells{current page.south west}{27}{35}{MyRandomColors}{0.2}
    \node[blur shadow, fit={($(current page.south west)+(9.2,5.2)$) ($(current page.south west)+(20.2,9.2)$)}, inner sep=0pt] (fitaux) {};
    \coordinate (aux) at ($(current page.south west)+(9.2,5.2)$);
    \ColorCells{aux}{11}{4}{MyRandomColorsTwo}{1}
    \node[align=left, node font=\LARGE, text=white] at (fitaux.center) { 
          Contributor: Dixie Wang\\
          Date: February 15th, 2016\\
          Filed: February 15th, 2016}; 
\end{scope}

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{70}{70}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(.25,1)$)
{Depression Problems and Active Modeling};

\node[rotate=90, above right,text width=26cm,
node font=\fontsize{20}{20}\selectfont\bfseries\sffamily,
text=titlecolor1] at ($(current page.south east)+(-5.5,21)$)
{(Spring 2016)};

\node[above right,
node font=\fontsize{40}{90}\selectfont\bfseries\sffamily,
text=titlecolor1!20!black] at ($(current page.south west)+(1,1)$)
{Jimmy Jones Jeremy};

\node[blur shadow, anchor=north west] at ($(current page.north west)+(1,-1)$) {\includegraphics[width=5cm, height=4cm]{example-image}};
\end{tikzpicture}

\end{document}

