Why was he staring at me like that?

I'm good friends with this guy and we had made plans to go out together and eat somewhere to catch up on life. We were both sitting at a booth and he was talking to me. After he was done talking, we both went silent for a moment. I had looked down for a second, but then when I looked back up at him, I found him staring and smiling at me with his head tilted to the side. His eyes were also slightly crinkled while he was staring at me. What does it mean when a guy looks at a woman like this?

Finds you interesting, and or attractive. It's never a bad thing.

Finds an interest in you.