Director Lan Hongchun took the stage at the 28th Shanghai International Film Festival to discuss how “ Dear You ,” now one of China’s most-talked-about films of the year, drew its emotional charge from qiaopi – the tradition of family letters and remittances exchanged between overseas Chinese communities and their relatives at home. The film has earned more than $255 million at the Chinese box office since opening in May, and carries a 9.3 rating on Douban. Lan spoke during the “Cultural Roots,