She doesn't

It's Jessica's nervousness that eventually gets the better of her. A hand over each breast, her body shakes with fear, which continues to ease her dress down. Suddenly the dress gives way, dropping all the way to her feet, suddenly leaving her stood there before the crowd in nothing but a red thong.

The cameras continue to snap around her and Jessica looks back and forth for a means of escape. In order to retrieve her dress she'll have to bend over, which will give those behind her a great view of her arse, and she'll also have to remove her hands from her breasts, completely exposing herself while she picks up the dress.

On the other hand she's only a few dozen paces from the bathroom, which could at least offer her a brief hiding place.