Portfolio and Failed Review Related Issues

Hello everyone, I am a newcomer who started selling video works this month. Some of the uploaded videos can pass the review, some cannot pass the review, and many cannot pass the review. I received an email informing me that it was a “quality problem”, but it didn’t explain what it was! Some of the videos that did not pass the review are obviously better than the ones that passed the review. Why is this? What are the judging criteria? Just telling me there is a problem without telling me what the specific problem is doesn’t make me improve, it’s no direction! It is still possible for me to upload a video with the same problem, which is a huge waste of human and material resources for the reviewers and myself.
In addition, during the uploading process, there was a prompt asking me to submit a “portfolio”, but what is a “portfolio”, how to create a “portfolio”, where to submit, and how to submit a portfolio have not found any articles that can fully explain. I urge professionals to answer

It is impossible for reviewer to explain every product rejection(there are so many projects to review), if you want to know what is wrong with your project post it in forums. There are many authors who will suggest what went wrong it. You can also check the product on market that are approved recently & know how your product compare with it.

do not re-upload already rejected project without making significant changes.

Can share the screenshot of this part because I didn’t found this option.