I was speaking more about normal DCU Joker in my comment-- for the Joker in this story, I think he's different from the 'regular' Joker in that his jokes are more in-jokes, jokes that he finds funny for whatever twisted reason that the rest of humanity might not see the humor in, so the rape could be in-character for him. However, I don't think the rape shown in the scans would be something the DCU Joker would do, because his humor tends to be more . . . accessible, if that makes sense.