If you read the poem slowly and think about it, you get this mysterious type of feel.
This explains the tapping on the window, and later the knocking on the door.
Therefore the mood is mysterious.
The subject matter is in the poem's title. Their is a resentful mood although it's not plainly stated that the author resented her mother. Her mother's house represents the attitude of her mother; the walls stood at attention, the air knew to hold its breath, the polished floor defied heel marks... The personification is plain in these opening observations and, given the subject matter, it seems plain that these are reflections of the author's mother. It would seem that her mother is very commanding, superior, serious. Two lines I think are very telling:
"crinkled in discomfort
in my mother's house"
It's not been named a childhood home, rather she's in (imagine italics) Her Mother's House.
What is the poem called ?
The main Character is Julia. Who is actually the author and the illustrator of the oak. So basically it is her autobiography.