Let’s say you’re Inez van Lamsweerde and Vinoodh Matadin, you’re shooting Yves Saint Laurent’s spring campaign with Stefano Pilati, and you have a bit of downtime. What do you do? Duh, shoot a sexy video. This hypnotic, slow-motion, black-and-white footage of model Arizona Muse (who also closed YSL’s spring ’11 show) fading in and out while writhing around a palm tree in a Marrakech garden will have you wondering if you just watched a four-minute mirage on YouTube…