Compared to the similar-themed movie "The Blue Kite", this movie is much more subtle and it tried best to ignore judging the government and the communist party. That is the reason why it can be launched publicly and the latter was banned.
In my opinion, the cut-broken photos are strong metaphors for the modern Chinese history. The photos are our history, yet, lots of tragedies happen, and the government or the communist party want us to forget the history, to erase the history liking cutting the photos. Yet, we the people can not forget the real history, real people, real tragedies around us; we can not let the real history being just erased off our memory.