Well, since Elaborate is a synonym for explain, I would guess that the student would just have to explain more about the topic.
Answer:
By noticing how the character interacts with other characters.
By noticing details about what the character says, does, and thinks.
By noticing how the other characters perceive the character.
By noticing the context, and use it to make inferences about the character.
Explanation:
Indirect characterization is the process by which the writer presents the personality of the character through different methods except for directly describing it. That is to say, the character is identified by the way he/she acts, talks and looks like, and this is how the reader determines what kind of person the character is.