  Although I had seen most of this movie in Chinese, this weekend was the first time I saw it with English subtitles. I must say, its worth all its hype once you actually understand what's going on. I think my Chinese is definitely not good enough to have got the actual plot last time.
Anyway, it really shows the pettiness of humankind -- how if we are put in a small box we lower ourselves to the standard of the box. Really, Songlian didn't even want to marry, and most likely neither did the other wives -- but when the limits are put around their world, and the road to their limited empowerment set, they concentrate all their energy on a petty war trying to attract their faceless husband for the sake of the power it gives them. It's interesting that these rules were set by generations of the family, and they have kept the women in line for ages.
It really works to keep them subdued and compliant, as if Songlian had decided to live alone in her room, play her flute and not bother with all the schemes to attract the husband to her quarters; she would have been able to stay quite happily for an age. However, because the whole household skips to the beat of the woman who had her lanterns lit the night before, those who do not have this special treat are unable to eat what they like, have the special massage or even get the servants to do what they are supposed to do.
There's a great quote where Songlian states that this is a household of animals not humans, and that combined with the fact that you never see the husband's face brings you to see Zhang Yimou (director)'s point that they do not see each other as people worthy of relationships, but things to be used to get what you want.
I think that's more common in these enlightened days than we realise too. How about programmes like Sex in the City or Friends, where the extras are merely sexual or comic objects, reduced to their value of entertainment or pleasure but not really seen as people -- except for the important main characters. And you can see this in student life too, where the reduction of people to objects -- notches in the bedpost, or the nerdy guy who gets to hang around with the cool people so they have someone to laugh at. 
