Perhaps that art is from an episode where the Avengers go to another universe? After all, Dr. Pym is not the Giant Man in that picture, Wasp's costume is different than that of season 1, and Rogue and Storm have variations of costumes never seen before in comics. Yes, i realize the art was conceptual only, but I am just trying to surmise what pre-conception the artist was working with when creating the characters looking that way.