The answer is:
The length and syntax reveal Gatsby’s excitement and arousal about being in Daisy’s large house.
In the excerpt from "The Great Gatsby," the author Francis Scott Fitzgerald suggests the excitement and exhilaration Gatsby feels at Daisy's house. For instance, he describes the bedrooms upstairs as mysterious, more beautiful and cooler than the others, and wonders what joyful and cheerful happenings and affairs might occur there.