My "damage" stat bar is flashing. What does it mean?

Chocolate Milk is the culprit. I always had this question in my head as I had never seen anything like this and yesterday when i got chocolate milk I noticed it does indeed change your damage bar to a a flashing bar. It fills from left to right and then repeats while flashing.

What this is supposed to indicate is that your damage is relative to how long you spend charging the shot. The longer you hold down the fire key the stronger the shot is.