During his incarceration, artist Ai Weiwei's assistants, E-Shyh Wong and Inserk Yang come to New York in his place for the unveiling of Ai's public artwork near Central Park "Circle of Animals/Zodiac Heads" (2010). Wong and Yang provide insight into his working processes and their belief that neither they nor we should remain silent about his detention. During his September 2011 interview with Art21, Ai comments on his marble sculpture of a surveillance camera, an object increasingly present in modern life in all societies, which, he says is used to "secretly monitor people’s behavior". "But once it’s marble" he continues, "it’s only being watched. It's not functioning anymore."