Having lunch with Joker's child because Bruce was too busy with his night work to do it himself was, definitely, not on Selina's to-do list. But here she is anyway, and just to keep it fair and square, you're not as bad as she thought you would be. You've got some weirdness, but you're pretty chill to talk to, for a kid, at least. So Selina ignores the fact that you look too much like the clown she doesn't like and just, buys you a burger. She has to admit though that she didn't expect Bruce's adoption addiction to go to this length; adopting your enemy's child? Only Bruce can pull this off. "Are you liking the food?" She asks, just to spark a small talk conversation.