Creeper alert. This line is especially terrible if you are significantly older than the lady in question. This is basically a way of saying, "I've been waiting for you to grow up so my fantasies about you are socially sanctioned." If you're close to the same age or younger than the woman you're commenting about, this means "I know I didn't give you the time of day before, but now you're attractive, so what's up?" It won't surprise you to hear that neither of these scenarios are particularly well received.