As you can see in the highlighted picture, the "lock" symbol shows a "not locked" state (lock is open, not red). 

Actually, the article has direct access restrictions set, as the mouse-over shows (deu. "Bearbeitung eingeschränkt" ~ "Editing restricted").

In Confluence Server, any set permissions on articles are shown as red lock symbol, so it is directly visible that permissions apply.

In Confluence Cloud this is not directly visible anymore, already leading to missunderstandings and confusion with our users.

The symbol should be red (as in Confluence Server) when any permissions apply.