Shopping malls and many other large buildings have fire alarms similar to this one. Don't you find that you just want to press on the glass? Every time I see one of these I have to hold myself back and stop myself from pressing that button. In fact, it took much restraint on my part not to press this one while trying to take the photo. I guess it's much like a dieting woman holding a slab of Lindt chocolate... irresistible. Well, almost irresistible.
The fire alarm in my office building is cleverly covered by a plastic flap that one would have to lift to expose the glass "button". It's a good thing too - I walk past this alarm 10 or 15 times each day.