Way back in Thor, the Infinity Gauntlet was oh-so briefly glimsed in Odin's Vault, a major piece of foreshadowing for a movie that wouldn't arrive for another seven years (that'd be like the first Iron Man explicitly setting up Ultron). But then, in the mid-credits scene for Avengers: Age Of Ultron, we saw Thanos picking up that big metal glove from somewhere that most definitely wasn't Asgard, something Kevin Feige further reaffirmed; that was a different Gauntlet. So... there's two? This is a plot hole that will only bother those who've obsessively picked up on all the background clues (and spent the better part of a fortnight compiling a list of every easter egg in the movies), so there's really no better way to explain it away than with another background clue - it's not a movie-breaking issue, but is still something that needs addressing if the MCU is going to maintain its illusion of a tight continuity. It could be something as simple as a throwaway reference in Thor: Ragnarok to how Odin has a bunch of fakes in his vault, or an allusion to there being decoy Gauntlets to stop anyone being able to harness the power of the Infinite Six - just enough so we can make some inference.
