Alguien sabe a que problema técnico en especifico se refieran?

The photo isn't sharp and it is too green. There is a green cast to the photo. The quality of the photo isn't good. (Not for stock photos.)

Examine your image at 100-200% magnification.  Adobe Stock customers expect highest visual and technical quality.

https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

Better luck with your next submission.

quizas este un poco desenfocada podes arreglarlo con photoshop y dar mas profundidad