So if the photos are encrypted, how do you check they're photos at all? Your solution doesn't exist because any such service offered will be immediately flooded

So if the photos are encrypted, how do you check they're photos at all? Your solution doesn't exist because any such service offered will be immediately flooded by undesired use. It'll spread illegal content ranging from video game ROMs to child pornography. Script kiddies will use it as a command & control server.