Rejected due to technical issues.

There is noise, especially but not exclusively  in the shadow area, shadows should be a kind of grey (either you had a coloured flash or the white balance is not right). The contrast of the white and yellow pencil against the background is not enough. Your highlight is probably too strong (yellow and black).

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