I guess you have to sign up to watch videos on Steepshot. I've never seen where you trap the leg with your off arm but I have a ton of success with the scarf hold. I can apply insane amounts of pressure while relaxing and I'll typically get a straight arm bar, kimora or americana by trapping the arm I have between my legs with my foot.
There's no video on Steepshot yet, so it's only a pic. I think he was just advertising the vid here to those users who only really use Steepshot, and not necessarily Steemit or dtube. He has the YouTube vid on his Steemit account though.