First, I agree with the reviewer Shan Bhattacharya.
What is the purpose of this film? For me it is to show the complex relationships between the state-level politics of countries and individuals who live in them and then the interrelations between the countries and individuals.
Sounds dry? Well, this movie is anything but! The above thematic is shown through a very human drama. There is conflict, compelling characters, drama, good dialogue for the most part, and a sense of menace that hands over each scene (once we understand what is going on.) Also a lot of subtext.
I think a viewer will need to have at least some basic knowledge of China, Taiwan and Hong Kong, the history and relationships therein, recent events and also some understanding of "Asian family values" (yah I'll go as broad as that) and Chinese culture to really appreciate a complex, nuanced and essential film, which, by the way is far from perfect.
I was not always awed while I was watching this movie, though fascinated, but after it ended and I saw all the aspects/threads and mulled on them and the interconnections I could only say WOW!
I am an activist and rebel type of person, a woman, rooting for social justice and democracy, and I am is happy to have seen a film with a strong if flawed activist-filmmaker woman protagonist and a film that reflects my concerns in the world rather than a more "vapid" perfect film about/on topics that I don't give a damn about!