Situation: I am pushing the bookshelf near the trash can with the trash can in my six o'clock direction.
Alternative situations: After reading the bookshelf that is on my right I start reading the one in front of me. After cleaning the bookshelf in my 2 o'clock direction and tossing the wipees into a trash can in my 8 o'clock direction, I am about to dust off the bookshelf in front of me.
Question: What is black and sitting on the edge of the desk behind me?