@Rapunzel
Your love of Tangled makes me smile!
@mikefan
The only image of Wall-E you see is him printed on the power disc itself. So it's an image of him straight from his movie or Disney's promotional images for that movie, same as the image of Rapunzel on the Tangled power discs is from the Tangled movie poster, not him in the Infinity toy-style.
@Nibelilt
Since the Doofenshmirtz disc has a picture of a weapon and is a round disc, meaning its a power-up, then maybe that disc increases the power of weapons held by the player's character?