Isn't this a beautifully descriptive passage? When writing it can be difficult to describe a house or the setting in a creative, original way, but this quote from the Great Gatsby does an excellent job. From "the frosted wedding cake of the ceiling" to grass... that seemed to grow a little way into the house" the room is vividly and imaginatively painted in a way that readers can connect with.
"the frosted wedding cake of the ceiling" Doesn't that perfectly describe the ornate white ceiling of a Victorian house? Wonderful.