It contains a story within a story within a story, which is interesting from the perspective of both reader and writer. And each story could stand on its own.
First, there is the old lady chronicling her life, showing us that each easily dismissed graying face holds an entire soap opera of affairs that she -could- tell, if she would tell.
Second is the life of the young girl/ woman, as she lives through World Wars and the Great Depression, marrying for money in an attempt to save the family fortunes.
Third is the tale of the brusque and sexy communist, hiding out and trysting with the heroine in stolen moments and dingy borrowed rooms.
Fourth is the science fiction love story the man tells her after lovemaking.
And I'm only halfway through the book. For all I know the story of the sister may emerge as its own tale as well.
One of the things that is instructive is the way the author shifts point of view. It shows that it isn't strictly necessary to choose one POV and stick to it. Not only that, she also shifts the way that she presents dialog. It's handled in the traditional way when the narrator speaks in the first person, telling the story of her life. Quotation marks break out the text in which people speak, as we have come to expect. But when the young woman and the man spend time together, their dialog is not separated by the standard punctuation, making it less real. Dreamlike.
The book shows me that you can drift away from standard approaches and standard handling and still be cohesive, still flow easily for the reader.
On the down side, I'm wondering if Ms. Atwood's name means that her editor pays slightly less attention than might otherwise be the case. The narrator has a tendency to ask rhetorical questions while following a line of thought, and then answer them. This ends up being a little bit distracting.
A minor issue, but it's encouraging to find small criticisms for good writers. Makes the goal seem more achievable.