beoShaffer suggests that they just have different goals - they are aiming to make themselves look good, rather than do good.

Agree with the part before the dash, have a subtle but important correction to the second part. While the explicit desire to look good certainly can play a role, I think it is as or more common for giving to have a different proximate cause, but to still approximate efficient signaling (rather than efficient helping) because the underlying intuitions evolved for signaling purposes.