You have nothing to lose.

Go to the shop, pretend to get attracted to a shirt but actually just want to approach her. When you are near her, say hi and smile. Maybe then ask her how she has been doing so far, working in uniqlo must be interesting (pretend to be amused at the benefits she gets), is it easy to layan customers at uniqlo? blah blah blah.

Before parting wish her the best sincerely. Hopefully you give her a good impression.
Or if you berani, you ask her out for supper tonight, say you belanja her.

Good luck bro.