User Management in Apps & "Admin rules"

Dear App Builders,
I’ve got a question regarding user management in Apps. What exactly does the “Admin rules are excluded” under Group access mean?
In my understanding, I can not give a whole group admin access to my app in the builder, which makes sense in regards to security. But why does the user then have the option to select “Admin”?
Thank you!!

You can give a whole group admin access.

It means for example:

User1 and User2 have the Access Right: Admin in the “User Access” section. Now User2 want to give Builder/Viewer Access to the group “XYZ” in which User1 is, too.

This would mean User1 would lose the Access Right Admin due to the group access right. To prevent this behaviour we exclude Admin rules.

To back up what @thomas.danzer mentioned: the highest role the user has “wins”. So if user has ADMIN but he is in group that is VIEWER he will still be ADMIN.

Hence, Only once published these access rules will apply means that publication state for the app will not be checked for admins