Photo not accepted, please help,tks.

Your preview image is too small to correctly check the asset, however, I think you have oversaturated the sky and thus introduced colour banding. You may also have noise. The image is underexposed, whites are missing. That is strange as I would habe bet that the clouds in the lighter parts have little structure, what @RALPH_L explains as no detail in the highlights.

Along with what @RALPH_L said, the horizon line is SLIGHTLY tilted. And I may be talking through my hat here, but I would remove all but the lower clouds and crop out just some of the massive blue sky. This 16:9 ratio would allow for copy and might make the asset more commercially viable. Something like below, but it's strictly a personal opinion.

The sky has artifacts and the highlights have no detail.