The metaphors that Atwood employs in this excellent novel frequently have the purpose of elaborating on the curious position that Grace Marks finds herself in as she is the topic of massive discussion and debate. As Atwood assumes the voice of Grace, the wry humour and slightly sardonic approach to what is happening around her can be detected in the metaphors she uses in addition to the horror of her situation, as in the following example when she is starring at the flowers in the Turkey carpet in Chapter 3:
They have petals the shape of diamonds on a playing card; like the cards spread out on the table at Mr. Kinnear's, after the gentlemen had been playing the night before. Hard and angular. But read, a deep thick red. Thick strangled tongues.
There is both a horror in this metaphor where the supposed petals are compared to "thick strangled tongues," which indicates the horror of Grace and what she has experienced and undergone. But there is also an ironic reference to the petals as "strangled tongues." Grace relates the petals to the diamonds on playing cards, the leisure activity of men, and it is the male doctors who do their best to classify her and tell her what is wrong with her, and therefore the use of this metaphor could also refer to their botched attempts to treat her as a medical curiosity and "diagnose" what is supposedly "wrong" with her.