A confusing interface

The other day while I was hanging out at the printer (I was actually printing something work related) I noticed this on the wall:



Looking at the sign, you see that when there is flames (burning sideways) you should hover you hand over the of to the left. Clear so far... But then I notice those two lights that does a nervous blinking above the letters "A" and "B" (It was a long document I was printing). Anyway a colleague passed and I asked if he new (who knows maybe its something that is completely obvious for an Italian, like the string on the toilet for example).



The poor colleague asked another one, and in the end I was send to the chief of security in the office, who looked at does blinking lamps a bit, and told me >>you ask too many questions. In case of fire, press button, and forget about blinking lights<<

Anybody knows what these blinking lights is? does your fire alarm also blink at your workplace?

So many questions... In the end I printed the wrong document.