Yeah, I couldn't find the right words to describe it, but he is standing perpendicular to the target line. I've only ever been taught square or very slightly open, maybe up to 10" open. I would think that his form would make it more difficult to be consistent, especially since it's so different from his other swings.
I'm asking because before I had a slightly open stance when I chipped, but once I changed to a square stance, I suddenly started to hit it better and more consistently.