What is an example of metaphor in the novel, The Widows of Malabar Hill?

When Perveen leaves her Swaine Adeney bridle leather document case at the Farid’s house, her driver responds, “The fancy London briefcase? It must be worth a lot” (116). It outwardly shows her professionalism, but the papers it contains causes Perveen to respond metaphorically, “it’s what’s inside that matters” (116).