My central belief is that the key to aesthetics is coherence. In 3d we essentially create artificial models of worlds, I contend that what makes these worlds believable is simply how coherent they are; how all the elements tie together under a set of rules which govern them consistently. This coherence spreads to all areas of a film; dialogue, design, sound, music, movement etc. Together they create a feedback-loop which reaffirms that what we are looking at is true. The human eye wants this aesthetic harmony.
It felt like I was reading my own thoughts played back to me. Earlier this year I wrote about the necessity of Visual Harmony, and how this visual harmony is the primary (sole?) determinant of the audience's perception of 'quality' in animated works. Here's what I had to say back then...
Basically, visuals and motion and shapes and forms all desire to be in harmony. When they are not then a discernable (if not defineable) dischord occurs. ....
Once you ramp up one area of the visuals into a higher order of complexity (say, lighting or texturing) then all other areas need to rise accordingly to maintain that harmony. ...
Drop the level of complexity in any area and you create a sort of "off-key" feel to the animated film. General audiences understand this. When the visual harmony is well done they immediately perceive the animated film as having 'quality'.... There is such a thing as animation that lacks complexity or realism or literalism but yet still has a high degree of quality, simply because all the pieces 'fit'. So complexity or literalism is not the equivalent of quality- visual harmony is.
It's very rewarding to see somebody else "getting it". Read O'Relly's article. You'll find quite a bit of neat stuff in there.