Although it's not a new phenomenon (we once lost a friendly wager over the fact that she'd made an appearance in The Social Network), we're still in awe of her ability to transform herself.
It's a rare gift. Emma Watson is a case in point. We've all seen the snaps of her toughing it up for The Bling Ring, but there's no denying it's our Em under the pink velour and water soluble (we hope) tattoos.
Rooney, on the other, always has us double-taking and/or questioning the photo captions as they land in our respective inboxes. And we love it. There's nothing quite like being kept on our toes.
Oh, and Rooney's our latest style icon too. Check out her sartorial evolution in the gallery below.