Your picture is missing sharpness and has a noise problem:
Look at your pictures at 100% and/or 200% magnification to check for defects. Especially this type of pictures needs to be perfect as they are abundantly represented.
If you are new to stock, you should consider these resources: https://helpx.adobe.com/stock/contributor/tutorials.html
Please read the contributor user manual for more information on Adobe stock contributions: https://helpx.adobe.com/stock/contributor/user-guide.html
See here for rejection reasons: https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
and especially quality and technical issues: https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html
I'm moving this to the contributor forum.
Thank you the information.