The bookstore flirts, are they sending me a message?

I've been going to my local bookstore for years. A few months ago I started to notice two young ladies (early 20's) that work there. They are very different, but both are very sweet! The first few times I saw them there, they would smile at me and toss their hair, magically "appear" out of nowhere within the store if I moved to a different section, etc. The funny thing is this...These girls have always dressed ok, but something recently has changed. The last few times I have seen them, they no longer wear plain, "earthy crunchy", drab attire like courderoy slacks with suede "jungle mocs". Now, all of a sudden it's like both of these girls have ditched all of their "school marm" gear, and now are dressing with beautiful skirts and heels, and they I have even noticed makeup on them. Did they all of a sudden change their personalities? I really cant believe this is the same two girls. Are they sending me a signal that they are "women"? I like the changes! What's the deal?