Review your photo at 400%. See the fringing on the right edge of the box. Also, the edges of the shadow are rough and the shadow on the left side edges seems out of place. Should there be shadows on the left?
You tell us the reason Adobe invoked. I'm convinced, however, that it is technical issues and the moderator had an easy job with this:
Why the hideous green background? I don't think it does anything positive for the image. And there's far too much of it.
Technical issues aside, unless you made the doll yourself, you may have an intellectual property (IP) problem. Stock will probably ask for a signed property release by the artist or doll manufacturer. If you can't provide one, Adobe Stock won't accept it for commercial use.
Read these links.
I absolutely agree with @Nancy OShea about the background!! Santa looks really ill! (He's looking green. So this isn't good if he needs to deliver presents 😞. Looking green means the person looks ill/sick.) The green background has affected Santa in that he has taken on a green cast. The composition could be better as well.