Pixel World Skulls | GPT is trying to tell us something

AI GPT servers have a knack for creating skull heads. Is it a deeper question that the machines are asking us to think about? Or is it the user who is to blame? However you do it, the skull is one of the more popular images on the internet. These skulls were all generated by prompts that I intentionally put the skull as the subject of the image. All but one, can you guess which one? Here is a hint it's not all by itself.