If a girl looks down when you talk to her or she blushes when you talk to her, is it an automatic sign of attraction, or just an indicator that you're the more dominant person?

When I'm walking around the city or at the gym, I'll make eye contact with everyone I walk by. Sometimes the girls will be with other guys and they look down when I look eyes with them after about 3 seconds. One girl that I started to talk to blushed a lot and just looked down the whole conversation. I think I am the more dominant person in those situations however, I'm dressed in sweats and don't look too hot that's why I'm curious. I am in shape though.