For good measure, add in the Dock's habit of floating on top of working windows, and you have little choice but to hide it. The objects in the dock, as you can see above, do not have labels. That works fine in the demo, since every object shown is completely unlike every other object. However, put in six or seven folders next to each other and the user becomes clueless. However, that takes time and, when dragging a document, ensures a high rate of serious error.
Identical pictures replace differentiating icons Using pictures instead of icons is a bad idea.
The fabulous demo shows documents, such as the Apple home page, with title areas featuring 500 point type that scale down nicely into recognizable thumbnails. Real documents are not so obliging. The Macintosh does need greater document-differentiation, but we don't need a picture of the first page. Only when a representation is significantly enlarged should it transform into a thumbnail image. Users cannot build motor memory Because everything in the Dock jumps around when you add new items, items do not have a stable location on the screen.