It's a good mood for what he intends to tell her. That nervousness he heard in her laugh is now visible in her body language-- feeling shy, seems like. Insecure, uncertain, but not dreading. Seems she understands that something important is about to happen. If that's the case, he's done his job.

Rather than tease or further bait her, he simply waits, watching with open invitation. If she needs the extra few moments to finish preparing herself, that's fine. There's a reason he's letting her be the one to come to him.