There is a little bump sticking out but I couldn't get a good picture of it. The inside of the eggshell is bloody, too. Searching for bloody butt didn't help. What is this called? It is doomed, isn't it?
I wouldnt worry too much. Keep that vent cleaned--maybe a dab of triple-anitbiotic ointment to keep it from getting crusty? It could just be some left-over rawness.