Ambient - The Simpsons way...

I have just noticed this ambient advertising for The Simpsons on I Believe in Advertising.  From what i can tell, being sponsered by the government in the UK to help tackle obesity, doesn't really work when encouraging the public to take the escalator. Any thoughts on the brands contradicting message? For other bits of Ambient Advertising, have a look here: http://www.ibelieveinadv.com/category/ambient-outdoor/