ELLEN POMPEO POSTS 'GREY'S ANATOMY' GIF OF KATHERINE HEIGL, SPARKING FAN THEORIES

© Eric McCandless/Walt Disney Television via Getty Images A friendly fan GIF or a potential Grey's Anatomy spoiler? Ellen Pompeo is continuing to toy with fans' emotions as it was teased following Thursday night's episode that "another person from [Meredith's] past returns."Ahead of Thursday's episode, Pompeo tweeted a GIF of herself in character as Meredith Grey goofing off with Kather...