I have a theory that no man could resist a girl wearing the smoldering gray eyeshadow Reese Witherspoon is wearing here. I have a feeling some of you are going to want to test that theory out. The basic elements: She's got a taupe eyeshadow dusted around some back eyeliner. Then on the bottom, there's a shimmery silver-gray on top of the taupe shadow and in the inner corners. Lovely, lovely, lovely. If you want to copy this look, try the taupe shade in the Pixi Eyeshadow Quartette or Avon…