Technical issues

Your photo has underexposed shadows; is too noisy and oversaturated. The horizon is not level. You have a sensor spot in the blue sky above the second sheep from the top.

I agree with much of what @PepeCastro has told you.  Underexposed shadows, lack of sharp focus, oversaturated colours, horizon is not level, noise, chromatic aberration and a big sensor spot in the top right corner of your photo.  And you need to remove the white border as well.

Adobe customers are looking for technically sound photos without filters and effects applied.  The customers can apply their own tweaks to the photos to fit their needs.

It's unfortunate the exposure wasn't better as it looks like it could have been a really good photo.

Have a read through some of Adobe's help files.

Do's and don'ts when submitting content:  https://helpx.adobe.com/stock/contributor/help/photography-illustrations.html

Reasons for rejection:  https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html

They may not have enough staff to explain why they declined, so this section exists so that we can all learn from each other. For my part, I think that your photography is very interesting as a composition and theme, but the animals are not clear, they are dimly lit and blurry, the low lighting almost always goes parallel to the blur, lack of dynamic range in the plane of the animals, and the horizon is very inclined, I also think that it is too much landscape on the sides, you should have focused the center of attention,