Fashion 'Girls' Star Rocks The 'Runway' - EXCLUSIVE CLIP Published 9:12 AM PDT, August 21, 2013 Allison Williams has quickly established herself as one of Hollywood's most promising new style stars and the Girls actress cements that status by serving as guest judge on Thursday's all-new episode of Project Runway. VIDEO - Girls Season Three, First Look! ETonline scored an exclusive sneak peek at Allison's Runway debut, which elates all the remaining designers. Watch! Project Runway airs Thursdays at 9 p.m. on Lifetime.