The effervescent Preity Zinta is set to surprise fans with her cold woman act in Karan Johar's "Kabhi Alvida Naa Kehna" (KANK). "I never like myself on screen. But I must say KANK has changed my look and my personality completely. I play this cold woman, which wasn't easy for a warm person like me to do. I have just a few expressions to give away.