“Self-aware cinema” is a nickname, that I just made up, to describe a kind of film that uses its style, genre, and characters to symbolize meanings that go beyond and even subvert the movie’s linear narrative. Well, that definition proves how hard it is to speak clearly about this kind of film. The idea isn’t new, but now it’s become sharper and more prevalent. An interesting recent example is Only the River Flows, from Chinese director Wei Shujun. The story takes place in a rural area of China, where the camera shows us, from behind, an old woman tending geese…