An example of indirect characterization is
He is considered a genius by those who know him well.
Step-by-step explanation:
Direct and indirect characterization have a difference of reliability in terms of the voice of the author in that the direct characteristics of a person are often variable without any personal subjectivity of a person usually by the other person's action.
Indirect characterization relies on what people say or recount about someone to know about their qualities and has a layer of subjectivity innate in it.
This is a telltale example of that because the person being talked about is touted to be a genius by those 'who know him well'.
This gives an air of subjectivity in the sentence.