If you'll recall, the first Thor film stirred up controversy by casting Idris Elba, a black man, as the character of Heimdall, the door man to Asgard -- not because the first black Asgardian is a door man, but only because Norse Gods are Aryan and thus presumed to be white. (I doubt it would've been the white power advocates objecting had Jarvis been made a black man, rather than A.I., in The Avengers and Iron Man.) The sequel, The Dark World, defiantly expands his role, having a lot more people, gods and various mythical beings enter Asgard, thereby keeping Helmdall busier than if he worked for a hotel in a 30s screwball comedy. The filmmakers also give the racist complainers even more whatfor by casting a lot of the Asgardian warriors as black (and one Japanese). See all those black dudes punching something or other in the background, or kneeling to the greatest of all Asgardians, Thor (played by Chris Hemsworth, a white man), after he proves his mettle in battle? I can imagine the decision made at the meeting: "this will really fuck with those white power assholes!" This is post-racial Hollywood, so I guess it doesn't matter that the servant is still black, just like Rochester, and the master who, like Mr. Benny, makes all the major decisions, is still blue-eyed and white. Perhaps simply applying black faces onto white mythology isn't the best approach to solving problems in representation.
The Dark World does actually bring up an interesting problem about representation in fantasy on film (sigh, DCP). One of the main evil dark elves, Akrim (the second in command), is played by Adewale Akinnuoye-Agbaje, a black man. Keeping with the film's racial sensitivity, he's the first major character to sacrifice himself for the cause. He doesn't exactly die, but instead transforms into a giant mutant elf, Kurse, with the actor subsequently completely covered in prosthetics and, I suspect, often rendered digitally (at least, in the battles). My question is does he still count as black representation? Too bad for the actual actor, but the answer seems to be 'yes,' since (1) in the fictional narrative of a novel, simply assigning a character as black (like Rue in Hunger Games) is enough to make them black, (2) a black character in a cartoon is an example of black representation (Green Lantern in Justice League), so why not this digital creation who clearly starts off as a black man? and, relatedly, (3) if the digital creation Gollum continues to be white, because of who he was as Sméagol, a white hobbit, the same rationale applies to the black elf becoming a mutant. (Not that any of this was probably thought about during the production of this movie.)