Re: That picture
I think the comparison is to anti-dandruff shampoos and how some of them are flammable which is why you need to be careful with domain registration companies because they'll either leave you scratching your head or on fire. You can also clearly see the flakes of dandruff in the picture.
Or maybe it could be to illustrate the anger of the customers at more price rises but what do I know? Who knows what goes through the minds of the people that pick the pictures?