The so-called "surprise cup," known in Chinese as a gongdao bei (“fairness cup” or “justice cup”), exemplifies both the technical ingenuity and the cross-cultural appeal of Chinese porcelain. Its operation relies on a concealed internal siphon, often ingeniously routed through a central figurine. When the cup is filled beyond a certain level, the liquid drains entirely through a small hole at the base, illustrating the principle of siphonage. In a Chinese cultural context, this mechanism embodied the Confucian maxim man zhao sun, qian shou yi (“fullness invites loss, modesty brings gain”). For European consumers, however, it was prized as an object of scientific curiosity and social amusement, an ingenious conversation piece displayed and demonstrated at banquets.