What does it mean when a girl lights up with you?

Greateye

Does this girl likes me?

Her face seemed to brighten up when I touched her upper back, why would she react this way?

Was she showing that's she's comfortable with me or something else?

What type of reaction is this?

Context:

There's a girl that I've met for some time, she seems a little exited to see me whenever I'm around. She doesn't mind being really close to her (even if we're touching each other). I kept making some conversation and making jokes with her. Then, one day, she was working on the desk so I decided to have a small talk to see how is she doing. When we almost finished our conversation I let her know that I would like to keep talking to her but I had business to take care of. When I touched her upper back, I saw her eyes light up and her reaction seemed that she like that I made that gesture (for some reason).

What does it mean when a girl lights up with you?
2 Opinion