Shooting directly into the sun is rarely going to result in a useful image. In the sky you have a huge blownout area surrounded by artifacts. The rest of the image is underexposed and over saturated, and the horse is not in focus.
Did you take this with a smartphone?
Be careful with shots like these. The sun will always come out as a big white burnt-out blob, as it is here. Shots like these will always be rejected! Always, it makes the foreground dark. It fools the camera meter's exposure.
For stock, don't bother with these kinds of shots!
Take a read of this guide to get you started:
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