Yes this sign means what it says..

How many times have you come up to the desk and seen the "I have stepped away from the desk and will return shortly, thank you"..

Under normal circumstance you stand there polity and wait for the desk clerk to come back.. BUT not where I have worked..Nope. most guests will start POUNDING ON THE COUNTER.."HELLO, ANYONE HERE, SOMEONE WANTS TO CHECK IN"..  As if that sign was a joke or the desk clerk really didn't mean she was away, she is just hiding in the back laughing..

I have come to realize that most guests either can't read or just think the signs are suggestion.. Employees only, do not enter, doors close at 10 pm. Pool is open at 10 am.  signs like these seem to confuse most guests.

we have an employee's only sign for our back office, I have walked away from the desk and come back to guests standing there jerking on the door as if to try and open it. "Oh there you".. I laugh it off because my boss won't let me punch them.  

Or the employee's only sign for our kitchen, most guests seem to think this means 'come in and mess with my stuff.' I have had to make sure this door was always  locked because I will walk in there to do breakfast and one or more guests are in there helping themselves to what ever.. "we figured we could.".. "what do you  mean we can't come in here?'. as if I am the bad person for making them leave, you can't just walk into the kitchen of a restaurant can you, why do people think it is OK for a hotel?  

the signs that are for closed or 'locked' signs are the ones that seem to piss people off the most.  Our pool closes at 10 pm.  Nope.. I will go out there and notice people have jumped our fence. "we thought we could come in because we are guests.."  the gate being locked means nothing to them.  "we figured the sign was for people under 18?"  as if we wouldn't have put under 18 on it..we figured they would just know it.!

some day I will actually read  a sign at my hotel and believe it.