What metaphors are used in Snow Flower and the Secret Fan by Lisa See?

Lily reports, “Mama nodded calmly, the monkey in her absorbing all this, but I wanted to fly from my chair, run down to the riverbank, and scream my excitement. I glanced at Aunt. I expected to see that big smiling cave of a mouth, but instead she had clamped it shut as she tried to hide her delight.” The nodding is in rejoinder to Madame Wang’s validation of the resemblances between Lily and Snow Flower. The allegorical monkey designates Lily’s mother’s restraint and mischief which oversee her discernment of Madame Wang’s clarifications.