Similar to Google photos, beaker://photos would be an area to simply host your photos. But each photo or album could be clicked on and shared with specific users (maybe this links into beaker://social connections).
So as I user, I want to be able to help my friends and family host photos without necessarily seeing all of their photos.
And as a user, I want to be able to share my photos with someone as well.
I think this basically exists today. But what this would do is wrap a nice UI experience on top of the functionality. So if someone is familiar with Google photos, the functionality becomes immediately obvious to them.