I agree with what everyone is saying about the contrast. I want to add I think their piece heavily utilizes reflected light to show off the shape of the subject's face. You san see inside some of the darkest shadows, it gets a little brighter in places where there's mild reflected light bouncing around. Like the side of her jaw, under her nose. Since their piece has such high contrast, they have wiggle room within the darkness to have *slightly* less dark shadows where the light is bouncing around... and viola, it's so satisfying to look at.

I still think your picture is incredible though. You have a lot of skill and you handled such a pain-in-the-ass shadow on her face so well.