It was a slow enough kick that he could have just blocked it, but he decided to show off instead. He bent his body backwards so that his hands were flat on the mat while her foot went over him, then he came back up and threw a kick at her, just a bit faster than she'd done at him.
"Here's a lesson for you. Always dodge if you can, it's easier on you than blocking." That, and I'd like to see you pull off that move. Maybe not exactly at this moment. Maybe a bit later on.