Ten rules. For each one, the sentence Amazon publishes, the reason a listing gets hidden, and exactly how the checker measures it.
Sources.
These are the technical requirements, not the whole policy. Amazon also reviews content, category and variation rules with a person looking at the listing. Passing all ten here means the file itself is not the reason it gets suppressed.
Check your own photo against all ten
One file, free, in the browser. No account and no upload.