The Great Gatsby Chapter 3 question

Sentence from chapter 3 for question: "A momentary hush; the orchestra leader varies his rhythm obligingly for her and there is a burst of chatter as the erroneous news goes around that she is Gilda Gray's understudy from the "Follies." The party has begun."

The brief sentence which ends the passage has the effect of?

a dismissal? an announcement? an overstatement? an explanation? or a contradiction?