The poster says the Great Wall took 1700 years to build. While this is technically accurate, it was actually constructed as a series of several walls built separately over that time by various ruling dynasties. Each new wall section built by any single ruler would take approximately 10-20 years to construct.
Andy Lau and Matt Damon both played the same role of an undercover gang member working in the police force: Lau played a triad member & senior inspector Lau working for the Hong Kong Police Force in Infernal Affairs (2002), and Damon played his American counterpart, staff sergeant Collin Sullivan of the Massachusetts State Police in its remake The Departed (2006).
When William (Matt Damon) was asked if he had been left behind before, he replied, "Yes. Twice before. And it didn't end well for them." This is a homage to his previous films Interstellar (2014) The Martian (2015), in both of which he was left behind on other planets and the expedition went wrong.