Saw it yesterday on some blog, but can't find it today to give the person credit, if you know where I got this thought let me know.
The point was that animator's use everything to sell the emotion, they try and make the entire body tell you what the emotion should be, it's what we're taught. If someone is angry, then we give them Angry shoulders and angry feet and an angry line of action and anywhere and everywhere we can we push the idea of Angry...BUT actors rarely do this, if an actor is playing an angry character they may only show it with a slight jaw clench (Clint Eastwood made his whole career off his jaw muscles).
Makes me think of JHD's review of the Illusionist and how long he kept his cool. Which makes me think of Paul Ekman noting that most emotional displays only last 4-6 seconds, then fade into more of a mood display. (could be wrong about that Ekman thing.)