So this is a mighty confusing sign. And one with potentially fatal consequences.
Imagine for a moment you can't read English.
What does the image suggest to you?
The reasonable take-away is that one should AVOID the stairs in a fire. It suggests that it will bring you closer to the very thing that you should be running away from.
The opposite interpretation is of course intended: that the elevator should be avoided and the stairs used in this kind of situation.
All of which goes to show it matters where you put the flames. Would it have been that hard to put them over the shoulder of our universally recognized stick figure?