At the film festival, founded by the late Roger Ebert, this weekend, Ebert's wife Chaz introduced the eccentric actress. "Tilda promised you that we're going to do something that they do at her film festival and film events in Scotland," she said. "We're going to have an audience dance-along."
Cue the music! "No observers," Swinton lectured. Even Chaz got into the spirit!
Watch the video below, which ends with Swinton and a group of audience members strutting their stuff across the stage.