As for the movie, she was fêting on her Greek getaway, James told us what it's really like to work with true icons on Mamma Mia! Here We Go Again. "Not only do I admire and respect the older actors—some of the living legends, Cher and Meryl Streep—but it's so inspiring as a young actor to be learning from them and encouraged by them. To observe them really. With the younger cast, we're just mates. It's been a bit of a mad journey for all of us. We're like, what are we doing here? We're on the ride together, and I really respect them all as well."
James also revealed just how close-knit the cast became. "My favorite memories are the people I met," she told Who What Wear. "We honestly have become very close friends. I think this movie is about celebrating friendship and sisterhood. We developed bonds, and I do think we'll always be friends. That doesn't always happen—in fact, it very rarely happens. To all be back together on an island and all frolicking around has just been heavenly."
Scroll down for an exclusive behind-the-scenes look at the costumes from Mamma Mia! Here We Go Again and shop James's favorite airport outfit.