It’s the “look back” part that’s important; it’s a subtle and often flirty way of checking to see if you’re still interested.
That smile is to let you know she’s pleased that you’re still checking her out and you should come over and start talking.
The most common example of preening behavior in women is playing with their hair – smoothing it down, twining it around their finger or brushing it slowly away from their face.
They also may start rubbing their neck or wrists; self-touching is another sign of interest, as it draws the eye towards those parts.
Not only should you endeavor to make eye-contact with women, you should watch for the women who’re trying to catch eye.
Someone who’s actively trying to make eye-contact is more likely to be open to an approach.
If the person takes longer – four or five seconds, say – then that’s a pretty strong indicator that they’re interested in you; there’s something about you that fascinates them.This is why you want to look for a particular form of eye-contact: the three-part glance.A woman who’s interested in you will often meet your eyes, look away (usually down or to the side), then look back again, usually with a smile.Of course, someone just giving you the hairy eyeball might be interested…or she might be trying to figure out why you remind her of that friend she hasn’t seen in years, especially if she’s got the “I’m trying to do do complex math” look instead of a smile.Sometimes she has enough courage in the moment to be overtly flirty but enough to pull the trigger herself.