Discarded plastic cups and bottles are so prevalent, they're almost invisible. Two artists are trying to make them and their impact impossible to ignore. They created two large inflatable sculptures, each about the size of a school bus. On a recent weekend, the artists — Jana Cruder and Matthew LaPenta — set up their sculptures in Pershing Square, a park surrounded by glittering skyscrapers in downtown Los Angeles. Passersby snapped selfies in front of the bulbous shapes and approached the artists to ask questions about their intention.