When Nilli Willis played with her pussy, she never once neglected her big tits. It's common for girls masturbating on-camera and the photographer filming her to lose sight of that once the girl really gets to work on her cunt, either with hands or toys. Nilli was trained well from the start.
Watch Nilli and see how her big, heavy tits move. Her twin melons never stop wobbling and shaking and she's usually fondling them, no matter what else she's doing.
Her regular photographer, John Graham, gave her complete, detailed, step-by-step instructions throughout this entire video, as well as her other shoots, and you can hear it since the original audio is intact. He was a tit-men and knew how other tit-men thought and what they wanted to see a busty girl do.
This is the difference between the average photographer who just films a busty girl masturbating and a boob-minded director who completely understands big-breast photography.