This image for the World Wildlife Foundation is demonstrating that the forests are the life force of nature. Clear cutting in the worlds forests is like killing a portion of a lung.
The two elephants and peanuts ad is a win because it conveys the idea that the peanuts are so large and tasty that even elephants, who eat a lot of peanuts can choke if they are not careful. The elephants also convey the idea of enormity.
The image of the melting polar bear illustrates that global warming is destroying the habitat for polar bears and other arctic animals.
This advertisement show a Volkswagen Beetle that has been "killed" by the bug spray.
This picture shows the duality of the surfaces. In the front you have a typical natural mountain scene whereas in the back you can see the construction scaffolding.