The 23-year-old star
-- who poses in a sheer Giambattista Valli dress for the magazine -- may not be doing red carpets any more, but she would like to expand her social media presence. "I want to be [on Snapchat]. I don’t know how to use it," she admits. "I feel like I’ll be an old lady that’s too held back, because I don’t keep up with it."