Final answer:
The specific details about Mr. Jeffries, Aven's art teacher, and the incident that embarrassed her are not provided in the information given.
Step-by-step explanation:
You have asked what Mr. Jeffries, Aven's art teacher, did that embarrassed her on her first day at school. Unfortunately, the information provided does not mention a character named Aven or an incident involving an art teacher named Mr. Jeffries. Instead, the details discuss a gym class incident where the student felt embarrassed for being asked to jump rope, a situation in a social studies class, and the experiences of individuals in different contexts, such as a Stanford graduate undercover as a high school student, Henry Ossawa Tanner's experiences with prejudice, and instances from literature.