Blake Lively covered up a fancy gown with a warm jacket on the set of Gossip Girl in NYC yesterday. She returned to the East Coast after a quick trip to Paris where she shopped with Christian Louboutin and celebrated as the face of Chanel's Mademoiselle handbag line. Her first ad for the brand was just released, and it features the actress holding one of their famous quilted purses. Blake's taking a break from her Chanel duties as she gets back to filming, but she'll continue to be surrounded by luxurious clothing and accessories as her small-screen character, Serena van der Woodsen. Her costar, Ed Westwick, enjoyed his own dress-up day wearing a tux for the cameras while Penn Badgley chose warmth over style. Penn also shared scenes with Connor Paolo and Chace Crawford. Jessica Szohr rounded out the group, though there was no sign of Leighton Meester.