Johanna is not easily impressed. She's been around enough to see all the little tricks and modification the Capitol is capable of. Surgeries and procedures, modifications and enhancements. Whatever, whatever, whatever.

This is nothing like this. It's exactly what he promised: flying, but low-level. He could go higher. And she could look for wire, or assume that she's mad (not out of the realm of possibility).

Or she could laugh. Which is what she does, surprised and amused and pleased. It's a good trick. She doesn't wear her surprise so openly--no blank stares, open mouth. But she does stare. How could she not?

"How'd you get to do that?"

Maybe a little jealous, too, even if she's assuming that it was something that was done to him. That's just her realm of experience. Nothing personal.