You know butt pose: It’s when female characters on movie posters are posed juuuuust so, enabling the audience a view of both her chest and her derriere, while any male characters get to face the camera and be all action-y. Here are some Avengers-y examples (scroll down). And a more recent one from Divergent. Here’s another. And another. And another. And another.
Tauriel has no truck with that nonsense. Now strike a pose, Legolas!