if you snap a picture, google will be a LOT more useful. they have a picture search function already, here's how you do it: http://www.google.com/insidesearch/features/images/searchbyimage.html
I first discovered this when I was trying to track down a wedding gown that I had seen..
however, I've got to say, make sure that the picture is very clear and a good close-up. if you can, try to remember the angle the stock photo you have seen was taken from. otherwise google will find you tens of thousands of similar pictures..