Maybe not exactly what you’re going for, but you might want to think about using the Welcome Pack Plugin for Buddypress. You can create a section on a “start page” about uploading picture. Other then that, I don’t believe there is anything that will constantly remind a user at the time.
I’m getting a warning error when going to any page other then the homepage.
Warning: Cannot modify header information – headers already sent by (output started at /websites/123reg/LinuxPackage23/ga/me/rf/gamerfold.co.uk/public_html/gamerfold/wp-content/themes/bp-columns/members/index.php:12) in /websites/123reg/LinuxPackage23/ga/me/rf/gamerfold.co.uk/public_html/gamerfold/wp-includes/pluggable.php on line 866