Why had these pictures been rejected?

I'm gonna read all the specifications I think, but it would be nice to have a specific answer because you can't improve when you don't know what's wrong and you're making a guess, which perhaps won't be accurate.

By @Jilmary

Moderators do not have the time to do that. Even selecting from several refusal reasons costs time. And then, moderators refuse at the first error they seee. They won't check further.

Sorry to express it as such: A contributor is supposed to be a professional knowing about quality and IP and anything else. Moderation is not done to make a better contributor of you, but to protect customers from bad assets.  If you have problems finding out about the possible causes of the rejection, Adobe established this forum for you to help.