From the passage we can see that when Melanie wanted help from the narrator with her math homework, the narrator refused to help her solely because Melanie was the unpopular student. The narrator didn’t wanted to become unpopular too by helping her.
Kim on the other hand didn’t bother about such things. All she knew was Melanie needed help so she should help her. From this instance we can say that the narrator is the one who thinks of what people will think, while Kim is the one who just think of doing the rightful act irrespective of the consequences.
Both the friends differ with each other in the sense of their thinking, their perspective.
