When submitting AI assets to Adobestock, do folks classify as "Photos" or "Illustration"?

I would think if the image is truly "photorealistic" than it would be classed as "photo", otherwise "illustration"?
There is definitely a large "grey area". What have folks been doing in this regard?

Yes, there is currently definitely a gray area.
There is an official guideline from Adobe with examples of images, but it is not clear when exactly the category for photos no longer applies.
https://helpx.adobe.com/stock/contributor/help/generative-ai-content.html

I would also assume that the AI Images have to be really photorealistic to be classified as photos.

For illustrations I would say e.g. for surreal illustrations, collages, obviously 3D content, etc.