Whether it's a hungry child in a war zone or a polar bear on a shrinking raft of ice, we're all familiar with shocking images in advertising. Companies use them to confront us with difficult emotions or go against societal norms as a means of grabbing our attention. Dettol, for example, once created an advertisement for its hygiene products that depicted a bloodied hand in front of the body of a man with a knife through his chest, alongside the words "When ordinary soap just won't do."