Natalia Vodianova plays Medusa in Clash of the Titans. Though fashion blogs have been mildly freaking out about this for a few days, the people who made Clash of the Titans don't seem to be necessarily capitalizing on her inclusion in the film. Nor are they making a big to-do of Agyness Deyn's appearance. Deyn apparently plays Aphrodite, and no stills of her on the set or clips of her in the film have been released.
This is how Grazia describes her role:
According to our sources, Agy spent about a week filming in London, although her role is a little bit blink-and-you’ll-miss-it - she’s basically standing looking gob-smackingly beautiful in the home of the Gods, but you wouldn’t necessarily realise it was her if you weren’t looking out.
Maybe they're trying to hide the models. We wonder if they let them speak lines. In the clip of Natalia as Medusa she just hisses and grunts.
Clash of the Titans: An unlikely fashion film! [Grazia UK]