Okay, first of all, that is not a good poster. Weird perspectives and no central idea. It’s just bad. They jammed a bunch of images in PhotoShop and then remembered there were still 3 or 4 more characters to include so they tossed those in as well.
But the most interesting part of it is what we can learn from the credits below. We already knew Don Cheadle was in from the early trailer but apparently characters from Thor and Captain America’s world are also in this one, as well as Iron Man. Stellan Skarsgard is back but so is Idris Elba as Heimdall. That seems out of left field. Anthony Mackie is back as Falcon but then so is Hayley Atwell. So will there be flashbacks in this movie? Hallucinations? Trips to hell?
Perhaps the most interesting element is Danny Elfman’s inclusion as “additional music.” He’s not doing the score but he is credited. Time for wild speculation: what if there was a post credits scene with Spider-Man? Wouldn’t a way to tease or confirm his arrival be to use Elfman’s famous theme from the Sam Raimi Spider-Man trilogy? Or maybe he just helped with, let’s say, Hawkeye’s theme. But I don’t think so.