Is it a dress or knee-length harem pants? See how the side seam rides up along the outer edge of her knee. There's tension in the fabric there. And the draping of the "skirt", a baggy wedgy maybe. Otherwise, a comfy look.
i love this outfit, so elegant and classic. but to spice it up, id add a colored belt instead of the black one. it would draw more attention to the thin-ness of her waist, and bring out her shape. but i love the simplicity.