Hey Kyle,
Can users already tag themselves in pictures uploaded by another profile so that the pictures appear in their media gallery and on Activity? That would be a great functionality to have and, if I got the way you have set up the programming right, not too difficult to do either!
Here is the usecase I have. Businesses who make eg trips upload their pictures. The users want to take over the "official" pictures to their own profile as well to basically have a reminder of the beautiful time they had. Instead of downloading and uploading again (also to save ressources), it would be great if that picture which they wanted to tag themselves in just got "attached to their profile", not as a new entity but as a "cross-link" basically.
Bye
Tim