My discord friends had some easy ways to defeat this.

You could require multiple photos; it's pretty hard to get AI to consistently generate photos that are 100% perfect. There would bound to be things wrong with trying to get AI to generate multiple photos of the same (non-celeb) person that would make it obvious it's fake.

Another idea was to make it a short video instead of a still photo. For now, at least, AI absolutely sucks balls at making video.