Don't try to explain to a friend what this movie is about, because it's not only about a woman running around and some other characters doing other things.
Try to explain him the way it made you feel. Try to explain him the subtle relations between characters and actions, even between characters of this and other films such as those of Tsai Ming Liang's (remember the grandpa and the little boy in "Goodbye, Dragon Inn"?), and you'll realize how difficult it is.
Now try to explain him the way you felt when your last girlfriend left you, when your dad died or you failed to make your daughter happy...
This is a fine film. Watch it. Feel it.