This isn't a particularly hard question, but it's one I find people generally aren't prepared for and it's definitely a harder question to BS if you're caught off guard. A quick interviewee can usually make up something if asked about their strengths, weakness, or a time they did such and such but if you know nothing about the product this question will show your interviewer that. Also, be prepared to put together an outfit, most interview include some sort of on the floor "activity" so it's best to be familiar with that particular store layout as well. Really we're looking to hire our customers, people that know and can represent our brand. Keep that in mind and you should do fine.
What if you never have worn their clothing?
Even if you haven't worn the clothing, if you're seriously wanting a job with the company you need to familiarize yourself with the brands and styles, not only is a a huge consideration in the hiring process but it will be vital to doing your job should you get hired.
I just saw you on the internet , and I really need a job , for any position I have no problem , and I really appreciate you if I get a good position in your company , which makes me want to come to work in your company is , because I need some jobs