From the title you know I have almost zero game, so get past that and help me out.

I've been making small talk with this cute girl who works in a shop I've spoken to her on 3 occasions.

First time: (full glam makeup, smoking hot) Normal customer interaction, but pleasant enough.

Second time: (minimal makeup) Seemed friendlier (spoke to me in a higher pitched voice than previous, talked/engaged a lot more than I did, face seemed more "animated", fished for a compliment which I didn't give)

Third time: (glam makeup again) Guy in store was talking to her as I arrived, seemed to be getting short, generic but polite responses from her. As I approach the counter to pay she "flashes" me this sort of "hey you, I know you, I'm pleased to see you" happy expression as the other guy continues to talk at her. I pay she says bye I return the bye as I'm walking out.

I've seen the fake customer service smile 1000's of times before and this wasn't it, in fact I genuinely don't think I've seen a woman do this before. I used the term "flashes" because of how quick it appeared and left her face.

So what happened? Does she think she's made a new "friend" (we all know what that really means)? Is she a prospect/potential plate? Or was it something random women do that I didn't know about before?