Although there wasn't much doubt, at least now we have confirmation that C-3PO will have a red arm in TFA. I also noticed that the guy in the box with the air tubes cooling him off towards the end of the video has several bird-like aliens popping out of the side of his costume, which I assume makes him the guy inside the first alien we got to see from TFA (he's called Bobbajo btw.). Apparently his head was, as suspected, hidden in the pile of stuff on top of the box on the alien's back. Presumably he then puppeteers the alien's head with his hands inside the box.
However on the more speculative side of things; could the animatronic head that we got to see early on in the video be Maz Kanata? It looks very similar to the concept painting. If you imagine in with blue paint and the head scarf they're practically the same. The second thing that makes me think it's Kanata is because it's being controlled by motion-capture. This short clip is clearly and early test of the mechanics of the head, and you can see on the computer screen with the small camera on top if it a digital image of a man's face moving in sync with a recorded (possibly live) image of a man moving his mouth. It is possible that this is some new form of motion-capture that is being used to control the articulation of animatronic puppets. If so we could be seeing an animatronic Maz Kanata and Snoke in TFA.
