and her teacup full of dark brown tears. (22)
There's that secret pain again, rearing its secret, painful head.
But secretly, while the grandmotherbusies herself about the stove, (31-32)
You get the feeling that everyone is hiding something. The grandmother especially. What a lonely state of affairs. We can't help but wonder if this household was doomed to be depressing from the get-go. We mean, haven't these two heard that sharing (your feelings) is caring?
The grandmother sings to the marvelous stove
and the child draws another inscrutable house. (38-39)
At the beginning of the poem, the grandmother and child were talking to one another. Now it seems they've drifted further apart and are more fulfilled by interacting with the stove and drawing. They're in separated worlds, totally isolated from each other.