More ideas have circulated since, including the the acting aspect that is part of the 'MERGE' idea. I remember watching 'Horton Hears a Who' thinking about the acting that the characters have, the Dr Suess styled designs somewhat complement the exaggerated actions. In particular the 'Who' characters are bendy and wide faced, which give the animators the freedom to play with facial expressions and over-the-top movements.
The Mayor has most of these traits, scenes with him are always captivating to watch. The character is rigged like he would appear in a late 20's Disney cartoon, his body is stretched and very bouncy almost like there is little weight to him. A good example is from the featurette that I have posted below, it demonstrates a scene which he appears in.
The featurette also covers other acting ideas, such as the pitching process the crew do. The director has to describe each of his boards out by acting as the character. The process is very amusing to watch but it helps the animators in achieving what the director wants on screen including what the actor does in his voice or perhaps the performance of the character on screen.
The featurette also covers the great idea of two simultaneous actions, one with Horton crossing the bridge of certain death and The Mayor going to the dentists office. What plays out, to a humoured effect, is a change to the stakes in both situations. The dentists office becomes much more distressing than the bridge, with The Mayor being poked and pushed around like in a slapstick silent film. The final product lends itself to an amusing scene as well as some tremendous animation.
The acting idea is something that I definitely want to express interest in my studies of my anthropomorphic essay, it certainly places very well in the CGI category.