Sometimes people upload pictures to my gallery, which do not meet the criteria for the gallery. I have added some rules at uploading, but sometimes it's just not clear. It would be helpful, when deleting a picture, I could select (or additionaly, add a comment), why the picture was not approved, so people won't get mad at me and all. I don't feel like looking for their email address all the time to tell them this.
would something like this be possible?
It's a good idea (in my humble opinion) and shouldn't be to hard to implement. If you've a bridged coppermine why not just PM your users in the meanwhile?
moving this thread accordingly.