Target Free Thursdays at Walker Art Center have a party-like feel, if you're into more observing and contemplating than talking. The $10 admission fee is waived from 5 to 9 p.m., and art lovers take advantage of the weekly bargain -- especially recently, as the popular Frida Kahlo exhibit closes Jan. 20. One of the many ways Kahlo expressed herself was in what she wore in her self-portraits. Many in the crowd of nearly 2,000 in attendance last Thursday night expressed themselves through their clothes as well.