Before the "Welcome" party for the Model UN students, there are scenes of Riley, Chloe, and their friends just hanging out around town. Notice that Riley's hair is in the straight style. Then, watch the group walk downstairs into the "Welcome" party club. You'll know that they are walking into the party because you will hear the music. Riley's hair is straight as she walks in. Then, when they show another shot of them entering the club, Riley's hair is curly!