In this passage, Nick describes the way in which Gatsby introduces Daisy to his house. Gatsby wants to impress Daisy, and we can see that he has thought of every detail to do so. Most likely, Fitzgerald decided to use this structure in order to create a vivid picture in the reader's mind that informs him of the things that Daisy will observe. The progression and flowing nature of the phrases contribute to developing the idea that Gatsby carefully planned every last detail of the visit in order to ensure that this went smoothly.