It looks like 'fake' and animation because it _is_ an animation. The dancing was likely motion captured and/or hand animated and superimposed onto the robots basic balancing control system.
I'm not sure what you are saying here. I think the intent is to differentiate between the "optimal" robotic control dynamics which is designed for safety, efficiency, and to respond to unexpected situations and "dancing" which is intended to either mimic human motion or some anthropomorphic version of it.
So it is "animation" of a physical sort designed to make it look like the robots are responding to the music naturally, rather than programmatically.
