It's not just that the ad's star, a plasticine version of sauce-maker and reggae musician Levi Roots, is more realistically proportioned and less cartoonish than the usual Aardman figure (compare his look to that of the characters in "The Pirates!").
It's those singing and dancing drumsticks, kebabs and sausages, which remind me of the fact that Aardman has always seemed kind of... vegetarian? Consider the non-kill rabbit traps and veggie-growing focus of "The Curse of the Were-Rabbit," or that the escape on which "Chicken Run" is centered was motivated by the farm owners' switch from eggs to chicken pies.
Or for more overt messaging, consider this this spot Aardman did for Animal Planet urging viewers to eat less meat for environmental reason. No matter how cute that shimmying chicken leg is, it does seem out of character.