Within the Walker Art Center's spectacular "International Pop" exhibit, which opens Saturday, are several works directly reflecting the impact that images from commercial culture had on the Pop movement. Most notable is Andy Warhol's "Campbell's Soup Can," but the influence was international, as seen in art like "Special K," a Pop take on the cereal box from Brit Derek Boshier, and Japan's Ushio Shinohara's "Drink More," which incorporates a Coke bottle.