This time he's coined the term Visual Harmony, to refer to all the different aspects of a film. The point being, you can have a lush oil painting look, but then if you move it with mocap it's gonna feel dischordant because all the instruments aren't singing the same song. He points out that the computer has a default type of motion (animates on 1's and smooth with perfectly consistent volumes) so even if you have a different visual look you're piece will sound out of tune if you don't find a way to get the motion to fit the look. Keith gives examples:
So far the most successful adventures in defining different motion styles in CG have been done by reducing visual elements. Pocoyo removes everything but the characters and primary props. The reason this is successful is because the motion does not need to live in harmony with any other visuals. In musical terms they can just sing the melody because there are no other parts to be sung. It's an extremely clever solution. Another successful result was Marc Craste's Pica Towers from earlier this decade. By removing color and subtlety of shading (much of it is very stark with little gradiation in values) he simplified the visuals which allowed him to employ a more limited motion style. The result was immediately satisfying to behold.
anyway, interesting food for thought
oh, and here's an interesting looking flat shade (except its not, the shadows are painted on and I think it's all self illuminated, but anyway, doesn't look straight CG)