Panel 1:
Girl is sitting on a bench, looking angry and upset.
Panel 2:
Boy approaches her, holding a comic strip he has drawn.
Panel 3:
Girl looks at the comic strip and starts to laugh.
Panel 4:
Girl and boy hug, and the girl forgives him.
Reaction:
The girl's reaction to the comic strip is that she laughs, which shows that she is amused and entertained by it. This positive reaction makes her more likely to listen to the boy and forgive him.