This was done in the past, Google saw it, and now either refuses to generate or doesn't emit the SynthID watermark for those images

You create an image so trivial that no one would care if it was AI-generated or not.

That's not really the point. I was wondering at what point of complexity the SynthID watermark is added.

I.e. it doesn't make sense for a purely white or black image, but as you gradually add colors or features, at some point they would want to add a watermark, but based on what? It's an interesting question.

You waste a lot of compute on overhead?