I just read James “Brilliant-On-A-Daily-Basis” Gurney's blog entry Interactivity. While he was making a different point, it got me thinking. (Don’t laugh, I do that sometimes.)
I love the genre I work in and because I love it, I would like to point out one of its biggest flaws: Sf/f people tend to love detail. But that’s not the problem. The problem is, because of this, many artists strive to render out every detail of a scene and therefore set each character and object apart, head to toe with minimal overlapping. To be fair, I think we are slowly growing out of this in recent years, but when the figures are seen in this way, the painting becomes static and lifeless. It's not often that we see objects so clearly and completely in life. By trying to perfectly recreate every detail of the thing, the viewer is left, paradoxically, with an impression that is less naturalistic. A painted version of annimation’s “uncanny valley.”
Greg Manchess on the issue:
Basically, it stalls the action and becomes a reference that’s emotionally vacuous. I think I find that the emotional element is often left out in favor of reporting what something looks like, and not what it feels like. National Geographic was famous for this approach. Rinse all human emotion out of the picture first, in order to maintain a cold scientific view of the subject, even when the human condition is what's being written about.
Nothing is set up perfectly in life, so when we organize life in a picture, we zap the strength out of it. Life is chaotic, and overlapping figures brings this feeling closer to the viewer because they are already familiar with seeing life this way, even if they are not aware of it.
Interactivity also lends depth to a picture. In a flat image, the illusion of depth is enhanced by overlapping. Just the impression of depth is enough to set the brain to work on imagining perspective & distance.