The instructions first show him built without the cape. Then at the bottom they
show him flying with the cape on. A lot of minifigs, particularly nowadays,
have a few different ways they appear in the play pattern for the set and they
decided at some point along the way that the only fair way to do it is the first
way the instructions show. Often it doesn't make the best version of the
minifig, but it can be applied consistently without bias.