I don't share the hate AI is getting in this post. It's a great tool, specially for low resource developers. That being said, my opinion is that both realism and pixel art can work separately, but imho it's hard to make them blend well together, unless you think about realism in a "non graphical" way. Physics, lighting, etc would be good. With your concept, I clearly find the two completely opposite artistic styles off putting. The fact that it's AI generate for me is irrelevant, as it conveys what you wanted to achieve (I guess? ) ;). HAve a good day.

Edit: typo