I think the model of review is not consistent. In my experience, Apple rejected my app for the first time for 'x' and 'y' reasons. The second time they rejected my app for 'z' reason,that was also present in the first version, so I waited another 8 days for another review.

Funny is that my app was rejected because it could potentially violates 18.1 and 18.2 in https://developer.apple.com/appstore/resources/approval/guid... the first time. The mentioned app by the policy, as bad example, is avaiable in the app store.