Always a very special moment, when a new Robin catches the Joker for the first time. Batman does keep recruiting them younger and younger, though. Sometimes I wonder if that man might not be 100% sane.
Kidding aside: I love this photo. I acknowledge that this photo only documents 1/125th of one second of their lives. But for that 1/125th of a second, they looked like a very cozy, comfortable, happy family, and very pleased to be spending the day together.
(I invite you to compare this photo to any "the candidate with his family" photo in any election campaign ad you've ever seen. This one is far more sincere.)
I also like what this photo says about the progression of comics/pop culture fandom. For these people, fandom something that you share with your family and not something you're into because it provides an escape from your family.