Photos rejected

Take note of the colour cast/tones in your images. A smiling shopkeeper, a therapist—too red; a young woman—too blue and exposure, and so on.

Numerous rendering errors. 

Missing teeth.

Disproportionately sized fingers.

Too much red tones.

Adjust color balance to neutral (RGB) levels. Customers can colorize photos after purchase, if needed.

• https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html
• https://helpx.adobe.com/stock/contributor/user-guide.html/stock/contributor/help/photography-illustrations.ug.html
• https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html

Look at the first image. like @Nancy OShea said, look at 200%. Examine the lines on the side of the buildings. Look at the lines on the brick street. Look at the corners of the balconys.

Don't assume that AI is perfect.  It rarely is.

Examine images closely at 100-300% magnification for accuracy and quality.  AI notoriously makes mistakes with details -- skin, hands, fingers, ears, facial features, teeth, background objects, apparel, tools, jewelry...  Fix mistakes if you can, or discard & start over.