What do you learn about Julian´s personality through August and Mom´s first impressions?

When the students take Auggie on a tour of the school, showing him where he will have homeroom. Julian asks what happened to Auggie's face; Charlotte scolds Julian for being rude, and Jack defends Auggie as well. When he gets home, Auggie tells Mom how the tour went. Mom is shocked that Julian asked about Auggie's face, and says that Auggie does not have to go to school; Auggie realizes, though, that he actually does want to go.

From this episode, we learn that Julian lacks empathy and loves attention. He is rude, and he is a bully.