why wasn't this accepted? I am new to this so I want to get better.

Count your fingers and you will see one reason to reject this. As for all the other errors that are surely present on this picture, post the original sized asset, as submitted here. We have no access to your contributor account. And my crystal ball is currently in maintenance.

Too tiny for us to see much. I assume Santa Clause was created by Generative AI.  And AI makes a lot of mistakes, especially with fine details like face, hands, eyes, ears, nose & mouth & hair.   

• https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
• https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html
• https://helpx.adobe.com/stock/contributor/user-guide.html/stock/contributor/help/photography-illustrations.ug.html
• https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html
• https://helpx.adobe.com/stock/contributor/help/generative-ai-content.html
  
  

Examine full sized images closely in Photoshop at 100-300% magnification.  Identify and correct all the errors if you can. 

Good luck.

Please provide the full-sized image as originally submitted. This is too small to critique accurately.