How does one of the girls realize that Trish had not been happy in a long time?

As all of the girls are reminiscing about happy times with Trish, one girl, Rachael, remembers when they were in their junior year of college, and she attended a party after an awards ceremony in which Trish won a prize for her student film. Late that night Rachael found Trish and four other girls bent over with their noses on top of a table. Rachael quickly left and never saw Trish again.