Walker's ability to hold up a mirror to contemporary pop culture incorporates satire, provocation and questions about the purpose of art today. His interferences with the everyday environment, from iconic advertising to brick walls, cause meaning to shift from the mundane to the unexpected. In Schema: Aquafresh plus Crest with Whitening Expressions (Kelis), the cover of a popular hip hop magazine is smeared in toothpaste and blown up to the size of a billboard. In the context of the art world, the colourful swirls of toothpaste become decorative and gaudy whilst pop singer Kelis is reimagined in the tradition of the nude. In creating an image that verges on the ridiculous, Walker challenges our assumptions and evokes issues of race, body image and sex in the mass media.