I don't think you quite get it, Cadbury wants us to imagine a world made up of chocolate, they don't want us to image the world we live in now as a place of chocolate. So teeth won't rot cause they will already be chocolate, the chocolate sun won't melt chocolate bridges because the sun is made of chocolate. If the sun was capable of melting bridges, then it'd be capable of melting itself.
The consumers are meant to think up of the exciting fantasy world because we'd find it more interesting, and more likely to buy the product, than if we were to just imagine our boring lives made of chocolate.
