Is there another way of wording this statement? Probably. But it would probably be a wordier statement to get the same message across.
Do doors have emotions?
The long and short of it is that we know what this sign means. The door pictured here cannot experience emotion, hence it cannot feel alarmed. We, the readers, know this and so we apply the meaning that makes most sense without really thinking about it.
We instinctively know that there is an alarm attached to the door and that it will go off if we open the door.
What are you testing?
Signs like the one in my optician that says, Ground floor testing now available, doesn’t really mean they test ground floors. I couldn’t help popping in and pointing out the alternative meaning though. Luckily I know them and they shared the humour but also admitted it could be better worded and they’d be wondering for some time how best to word it.
As they are an optician we figured that everyone would know what sort of testing they were offering and that ‘Testing on the ground floor available’ would suffice.