First off- Introduction. What are you going to be talking about in the essay? Yours will be about what we can learn by seeing ourselves through the eyes of others.
So ask friends, family, or classmates how they see you. Then, use that experience to write how it helped you.
Maybe you realized that you need to be a bit more open, and communicate better. Or maybe you realized you weren't that good of a friend. Or maybe you need to spend a little more time with mom. Write about those experiences, and how they helped you grow as a person.
(I'm not writing you the essay, but I hope this helped!)