The pic itself is pretty awesome, showing Whedon hiding from the camera (and the actors’ eyelines) during the big lab scene, presumably when they all start yelling at each other.
ILM Works Its Magic on ‘The Avengers’
Although roughly a third of “The Avengers” is set in New York City precious little was actually filmed there. ILM crew members photographed 7-miles of city streets from a variety of heights and at different times of day totaling 250,000 images. The crew then digitally recreated roughly 20 square blocks of mid-town Manhattan using a variety of techniques. Live action shoots were held primarily on sound stages in New Mexico and in the streets of Cleveland.