Spent a few minutes looking around for something on the profile page to flag a user's profile picture for potentially inappropriate content. Is there any way to do this?
Instead, you should just flag one of the user's posts or use the "contact us" form at the bottom of the page.
But before you do, take a moment to read this answer which clarifies the way we think about potentially offensive content in user profiles.
At one point, we did let people raise flags on other people's profiles for just this sort of situation. As it turns out, people used it to complain about users they didn't like for whatever reason. So we took away that functionality.