I can see by the way she's sitting that her posture was not good for a photo. The shoulders scrunched up and the neck is not taut...it's gonna be tough to make a flattering shot with her shoulders, neck, and head in that type of posture. You needed her to be standing, tall, with neck up, and her chin somewhat projecting, and with the camera position higher up, to counter the double chin effect. Have you seen Peter Hurley's video about ,"It's All About The Jaw?"
Beside that, the lighting is very broadly sweeping across her entire face, making it look full, and wide, and round. This type of lighting pattern is illuminating not just the mask of her face, but every square millimeter of her face and neck and jaw.
Look at the 5:39 mark.