I often wonder to myself why signs like this one (especially in shops and restaurants) seem so aggressive. They have signs to welcome us and make us feel as though we, their clients, are super-important to them. In their marketing messages they even call us "valued clients". However, in their store or restaurant their signs are devised to be aggressive and intolerant. What's with that?
How about "No need to peek, there's nothing but very busy elves behind this door. Ring this buzzer or call 0800 555 1234 if you need a human's help."? Doesn't that sound a little more friendly, and a little more useful?