HOLY CRAP!
I hadn't noticed that, either! Is it really Loki, or could it be Malekith? He can transform into other people/forms, too.
But why turn into Loki in the first place - he is a prisoner, Malekith can't use that mask to walk around the palace. Is he distracting the guards while the real Loki tries to escape somewhere else?
Argh, I need to know.
I will never make it to November 20. AND I will have to watch it dubbed then. Boo.