He may look down, but Mabel is still absolutely thrilled. She's bobbing on her heels and can hardly contain her excitement, really. She saw that smile. Or at least, she saw an expression that she assumed to be a smile as it was somewhat different from his usual demeanor.

"That was amazing! For your first bouncing experience, you did great! I mean sure, the castle's never gonna recover from that, but who cares! You totally had fun, right? Just try to tell me that wasn't fun. I dare you--No! I triple-dog dare you!"