Mendes looks up to Blair Waldorf from Gossip Girl and Summer Roberts from The O.C. because they're strong, confident characters. "They say it like it is, and they're in control and are confident and have a lot of pride," she told Glamour.
Mendes explained what sparked that inspiration in an interview with The A.V. Club: "Even when I auditioned, I remember when I first went in, I was dressed really dark, more like an edgy rocker girl from New York. They're like, 'No, no, no, this girl is preppy.' So the next day at the audition, I went with the little skirt thing, and they're like, 'Wherever you can wear pearls, wear them.' I was like, 'Oh, I see.' They're like, 'Think Blair Waldorf.' So then I came up the next day looking more like Blair Waldorf. And I was like, 'Okay, now I understand who she is and in the context of the characters we've already grown up with.' But I also, I was a big O.C. fan myself, and Rachel Bilson was one of my idols. I loved her character of Summer Roberts. In terms of Veronica's humour, I channel Summer Roberts a lot."