B-Rolls usually have an awkwardness. Actors go through the motions of physical action scenes, or deliver dialogue heavy with portent without the support of vfx, music, or sound effects. It looks like a high school stage play rehearsal.
These two more so than most. There's so much green-screen in a movie like 'Thor' it's almost painful watching making-of footage. These guys just look so silly standing there, in character, reacting to the director's narration describing action from an invisible player who will be added months later using CGI.
But, that being said, shining through it all is a sense of hard work and conviction that goes into each second of raw footage. Especially in the second roll, in the scene with Hemsworth and Anthony Hopkins.
Kenneth Branagh shows a lot of confidence. Seems there was good energy on set.
All in all, easy to watch. Makes me want to see the movie, which, frankly, I had no intention of before.