I agree about the flames. They do look odd and remind me in a sense of animal hair (specially the flames coming from the top of the bottle,) albeit red, orange, and yellow. Even so, the gag still comes across.
Fire - or should I say flames - are, indeed, probably very difficult to capture. Even on television and in movies, flames (such as those in a fireplace, campfire, or even candles on a birthday cake) never quite look right to me. They always appear too white and lack the subtle nuances of ever-shifting, flickering flames that one witnesses firsthand. I suppose one way to compensate for this (in painting) would be to add more color such as orange and even red, but then you run the risk of creating a cartoonish-looking fire which is what we have in "Scorch" or "Blisterine."
Below is a photograph of a campfire. Not a bad picture, however if we were there in person, those flames would look quite different. They certainly wouldn't be white. (When has anyone ever seen white fire?) And I strongly doubt the flames would be red, either. Yeah, I'd say that fire would even present a challenge to the best of artists.
