Image quality issues?

Hello, it’s my first time in the community here.

Recently, I uploaded my photos for reviews and they all got rejected.

I just want to know if there is any specific standard for reviewing photos.

It says the photos got turned down because of quality issues.

I couldn’t find any more specific explanation from the review team,

So I decided to ask this question in the community.

(I don’t know how to contact the review team, too.)

I’d appreciate it if you can pinpoint out the problem of the following images.