The Use of Rhetoric in Graphic Design

Originally I thought this was the end of a sewer pipe but it's actually a can of paint. The idea is that a single tin can pollute millions of liters of water. The poster design is for WWF Spain.

I think there's some hyperbole here in that they've made the tin so large to get across the idea of the scale of damage that a single tin can do. Is there some allegory here too in that a paint tin turned on its side does look like the end of a sewer? A tin of paint literally turned on its side does spill and therefore make a mess: allegory used to symbolize a principle.

From a collection of adverts at guardian.co.uk