Fight fire with fire
Generally, a pictorial sign serves to label items for people if they can’t speak or read the language. So should you need to extinguish a fire, you should be able to follow signs for the fire extinguisher and know that you are getting exactly what you need.
In this case, I’m not sure that anyone looking at this sign would be 100% certain that they would shortly be putting out a fire. The flames coming out of the nozzle lead me to believe you could just be pouring flames on the flames.