The pair at the Two Panda Deli, a fast-food Chinese eatery in Pasadena, tend to blur their words drunkenly when their 12-volt power cells run down, and they’ve been known to drop food and spin in circles when police radios operate nearby. They’re programmed to be nice to customers — “Will there be anything else?” and “See you tomorrow” — in Japanese, English and Spanish. Patrons whose commands confuse the pair get the response: “That’s not my problem,” accompanied by a short blast of disco music to which the bubbleheads dance back and forth.