From an engineering point of view, what is wrong with the crazy crate?

[Slavers]

I am doing an Engineering graphics course through correspondence. The following question is a discussion piece for my class. I have already completed it, but I am wondering what others would say about it.

Here is a drawing of a wooden crate. However, there is no way to actually construct this crate out of wood (as shown). Please explain from a Graphical Engineering point of view why it cannot be constructed. What's wrong with this drawing?


The crate being refered to is the Crazy Crate optical illusion which is locate here: http://puzzles.about.com/library/weekly/blopil18.htm

[PETER T]

From my poitn of view, the rear-right vertical member and the rear-bottom horizontal member are drawn so that they are infront of members making the front plane of the box. Clearly this is an impossible situation. However, if you are really clever you could construct a box like this that when viewed from a particular angle looks like this, but when you look at it from another view point you can see how the illusion is achieved.