A beaker full of death wrote:
Yes. All three images (Jesus, Robin, Supergirl) seem to be of a parent (figure) holding their own slain child (figure) - someone they had responsibility for. It's not just two superheroes. It wouldn't be the same if it were Batman holding a slain Superman. It seems to me there's an instant attribution of the survivor's responsibility for the life - and therefore the death - of the child figure.
Just pulling this out of my ass as I go. More thoughts welcome.
There's the scene in Final Crisis where Superman carries Batman's body, I suppose.