California Gurls features Perry as a game piece in Candyfornia, whose settings are inspired in part by Alice's Adventures in Wonderland, Charlie and the Chocolate Factory, and the board game Candy Land. It's most famous for the scene in which Perry defeats an army of gummy bears by using whip cream guns attached to her breasts.
Boom Boom Pow starts with Taboo flicking through pictures on an HP TouchSmart. He selects the image of an explosion. The Black Eyed Peas are then seen singing their verses of the song. While this is happening, dancers are seen in striped zentai suits, dancing to the music, and negative images are turned into positive images.
Many YouTube celebrities joined with the band to film in the video. The video shares some thematic similarities with the music video for the Barenaked Ladies single "Sound of Your Voice," which also featured multiple YouTube celebrities.