We have native English speakers at my company.  (Literally, I sit across the hall.)

Only.. they refuse to check the phrasing on the signs before they post them.   So, you wind up with signs that make no sense, unless you read them in German, or try to make an educated guess.  In this case, I suppose they want the door securely closed when you go onto the terrace.

I’m starting to take pictures, and I am considering going through and correcting them… I wonder if they’d notice.