The famously otherworldly and enigmatic Oscar-winning Tilda Swinton talks to Amanda Fortini about her boozy new film, the joys of her open marriage, and why she would rather be a poet. Tilda Swinton is a paradox, a contradiction, a still point at which opposites converge. Her chameleon face is at once Victorian and futuristic, extraterrestrial yet earthly—her finely etched features appear to be carved out of clay. From one angle she is a handsome, somewhat masculine woman. From another, a handsome, slightly effete man. She seems to straddle time, eras. She often looks ageless; at other moments, all of her...