The subject of the profile can be someone you know such as friend, family.
It can also be someone you interview with.
The essay should show what special about the subject person.
The following is my instructor requirement:

you will utilize three sources of information: your observations (including background information), your subject’s statements, and the statements provided by their acquaintances to build a profile.
Your goal is to not only acquaint the reader with your subject, but to make the reader care about him or her. You will need to establish a clear context into which you have placed your subject. Incorporate description, anecdotes and quotations from your subject and acquaintances to build a well-rounded view.
By the end of the essay, the reader should have a clear idea of who your subject is and what context he/she has been presented.