The "scared face" greeting?

What do you usually mean when you give someone the "scared face" look for lack of a better description? Like when you walk by someone and make eye contact, you raise your eyebrows, widen your eyes, show your teeth but without smiling?

There's this girl at work I kind of have a crush on. She's super shy and really quiet. We get free daily frozen yogurt at our work so I figured that would be a good way to get to know her better without being obvious and asking her out...

I messaged her through our work I'm client and she responded she doesn't eat froyo unless it's her favorite flavor ____ (which they don't have this week - she's also very health conscious so I believe her but I feel like if she liked me she would've said yes...), and asks if I wanted to talk about {project we're both involved in} to which I reply nah I just wanted to get froyo. She never responded after that.

I walked by her later as she was on her way to go home and she gives me that look I can't describe. Normally she smiles at me a little so I don't know what on earth that expression means... I know I've definitely seen it before and used it myself but still don't know what it actually means...
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+1 y
Yeah I think maybe on second though "surprised" is the better word than "scared"
The "scared face" greeting?
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