Women are more perceptive than many guys give them credit for. Much of the PUA literature reads as if they are giving you secret knowledge that will allow you to get (control) women. Thing is that most women (over 21 at least) are very well aware when guys are players and are gaming them. I would go as far as to say that most women are turned off by guys who are players or are perceived as players.
The guys who are naturals know that it is not the game that you play but rather the connection that you make. While you were playing your game, your brother was making a connection with the girl.
Time and again I’ve been out with friends and they’d be playing the women and I’d do little more than look a girl in the eyes, connecting with her that way and then everything else is just us playing together.
So, for instance when your brother says something like, “I want to smell your perfume before I leave” it may sound really lame to you and make no sense that she would respond positively to it. However, if your brother and she had already made a connection then it makes sense. It’s not what he says, it is just that he is talking to her, that they are interacting.