Dosent matter. I interviewed for a seasonal Kohl's job in a business suit and heels. You know what that got me? Respect. I was treated with much more respect, they were quick to give me responsiblities first. They put me, untrained, into the customer service department rather then on the floor.
I made a point to not make them regret their choice and when I left they basically begged me to stay.
First impressions are essential no matter what job you interview for.