Auggie is feeling like he is going to cry but laughing at the same time because one of his friend named Julian ask about his face why it was like that then after that he ask “did you get in a fire accident”? Then after that he started laughing because Jack Will smiled at him which made Auggie smile back to him. I think that is why I think he is having that feeling. Or he laugh because someone told him a joke about Mr.Toshman and Miss.Butt.