Treating him like a misbehaving schoolboy is so clever. And the entire time he's writing I'm sure he'll be thinking about her and the awful fix he's gotten himself into.
I love her smile when she's thought of it. It was so good I even decided to overlook the continuity error of the fact that she has for some unspecified reason put a shirt on in the last pic.
She put the shirt on between the second and third picture because she wanted to give him time to worry about what she had decided to make him do... and also to give him a teasing peek at what he can never have.