While I’ve heard it used for that, I’ve also heard it in another context. I saw this woman walk into the library. I smiled that little “Sorry I’m looking at you” smile, and she smiled back, and held it a little longer, so I similed back at her. She came over to sit across from me on one of the computers. I went back to what I was doing, looked up, and she was smiling at me, so I smiled back. I looked up a few more times, and she was doing the same thing. She then says “Oh, I’m sorry. You just look like someone I know. You have these kind eyes.” She later gives me her email address and tells me to write.
So I think it depends on context.