Girls in the gallery scene, with swarms of narcissistic curators, exhibitors, and art enthusiasts alike, don't want to be approached by the guy who “thinks” he knows about Jackson Pollock just because he saw a cheesy documentary about him. Instead, take a lighter approach and ask her what she thinks of the piece. If she seems genuinely interested, give her your opinion. Simple and straightforward is the way to go, especially if you’re a gallery newcomer.