Here, "swank" is used to describe the party's luxurious and stylish nature, even though it's now in a state of disarray.
Here are some other examples:
* "He drove a swank sports car that turned heads wherever he went."
* "The new restaurant had a swank atmosphere with velvet booths and dim lighting."
* "She wore a swank outfit that made her feel confident and glamorous."
Note: "Swank" is an informal word, so it's best used in casual settings.