Berserk Button: Envy does not take it kindly when Greed brings up that the former's default form is "ugly". The only reason Envy doesn't retaliate Greed is because Father forbids it.
Foreshadowing: When Greed says that "that thing" Envy turns into is "ugly", the latter turns vicious and threatens to beat Greed within an inch of his life. On two levels does this come into play later. First, it sets up how Envy has a different default form, the giant dragon monster. Second, it frames the reveal that Envy's true form is a weak, ugly little worm, and resents their true form for it.
Wham Shot: When King Bradley's eye patch falls off, his scarred eye opens... to reveal an Ouroboros tattoo in place of an iris.
