It turns out that all of the dresses that the girls wear throughout the episode were actually the same dresses from the cotillion episode earlier in the series. Valerie Campbell, Gilmore Girls's key costumer explained that they reused those white dresses and dyed them for the season 5 season. As written in Teen Vogue, 2016.
Jared Padalecki does not appear in this episode but you hear his voice on a voicemail to Rory.