I have a theory about covers like this, or Superdickery-ish covers from the Silver Age, which usually depicted Something Your Hero Would Never Do or Something That Cannot Happen. Obviously it was designed to create reader curiosity, but I also think--based on when I would ALWAYS buy a comic with this kind of cover when I was a kid--that this sort of cover embodied the secret wish of the kid. Same reason Earth-3 was fun--we WANTED to see superheroes being bad.(Robin inspired at best envy and resentment, not identification, in kids, certainly me.)