Your picture is not sharp, it is oversaturated and the deer has been badly pasted into the image.
If you want to digitally compose pictures do it in such a way that it is not to be seen. It's quite demanding and asks for a lot of editing skills as well as knowledge about photography, light directions, lens behaviour and colour matching.
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 agree with Abambo. Compositing is an art form of its own. To do it convincingly requires time, patience and know-how. For tips from a pro, look at Jesus Ramirez's tutorials on the Photoshop Training Channel (PTC).