The small girl smiled shyly after completing her piano solo.
Indirect characterization is when the character's traits are shown to the reader through the character's speech, thoughts, actions, effects on others, and looks. Direct characterization is when the character's traits are specifically said. The first option specifically tells the reader that the teacher had a great sense of humor. The third option states that Samuel was anxious. The fourth option states that Luke is an excellent writer. All of these options are examples of direct characterization. Option 2 is indirect characterization because it doesn't actually say the girl is shy, just that she smiled shyly.