Generate AI images rejected - image quality

Hi everyone, 

I have been trying around with AI a bit and uploaded some images labelled as "generative AI" to Adobe Stock. However, my images have been rejected with the reason "image quality"/"quality issues". I'm looking for advice on why exactly they have been rejected, as it is not specified by Adobe. Would be really helpful to know in order to avoid these mistakes in the future, or to even change the images to an acceptable state.

Any feedback would be greatly appreciated!

Thanks so much!