You'll spot this one n the very last scene of the film (great cast, BTW), as the two main characters run out onto a rooftop to deliver a message to Dick.

Watch Michelle Williams carefully as she and Kirsten Dunst run away from the camera out onto the roof. Notice the huge dark spot right in the middle of the small of her back. That's obviously a huge layer of makeup designed to cover up Michelle's tattoo, which her character certainly wouldn't have sported.

Let this be a lesson to you kids with your crazy tattoos.