Eventhough you knew the reason behind the case, it still sounds like you are quite not happy. Well, let me explain this. Moderator's job is to monitoring the forum. Deleting failed posts is one of the tasks. Since that post was not working (as Idolfun mentioned), there's nothing wrong for the mods to delete it. If one of the link in your website is not working, you would also clean it up isn't it? Same theory. In fact, the mods won't delete a post without giving a reason. So there's no one against your photos. It's becoz one of your posts is not working, so we cleaned it up. As simple as that.
Action been taken and the reason been given to you as well. Hope you can accept the fact and no hard feeling in there.