From a Huffington Post discussion of aesthetics by Colm Mulcahy
of Spelman College, Atlanta:
"The image below on the left… is… overly simplistic, and lacks reality:
It's all a matter of perspective: the problem here is that opposite sides
of the cube, which are parallel in real life, actually look parallel in the
left image! The image on the right is better…."
A related discussion: Eight is a Gate.