Straight forward, my suggestion would simply be implementing the "quote" feature aswell as report button to the photo gallery.
Maybe people do not use the gallery all that much for uploading public photos but rather unlisted ones for themselves but for the ones that do, it would be nice being able to reply to posts being made in your own public photo aswell as report them if needed.
Let me know what you guys think of this suggestion.

Excuse my poor photoshop skills but this is what I was thinking.
