Please Welcome to the Stage: Every Single Surprise Taylor Swift Guest

Who?! She's an Australian model who first broke out at Paris Fashion Week in 2011. She walked for both Marc Jacobs and Jean-Paul Gaultier, and her career has seriously taken off since!
Where?! At Taylor's show in Chicago.
Why?! Unclear. Andreja wasn't in the "Bad Blood" music video, which featured tons of models. She didn't walk in last year's Victoria's Secret Fashion Show, either. That said, maybe Tay met her through one of their mutual model friends.