Yes that is binding adjustment. You find the grooves on the inside and that thing you pulled at the end, should go in. You should push it over, then when it starts to get tuff, you moves the strap and it should be easily put in.
That's what I figured, but wanted to get that out of the way...the piece I pulled at the end is what I'm really having trouble with...does it take a lot of effort because it doesn't seem to lock in place when I pull it like I did in the video.
Just bought the 360 Rome Boss bindings aswell and the guy at the shop showed how to strap it a couple times. When i tried it i also had trouble getting the right binding in place (tweaked a bit and pushed down). After a couple times i got the feeling and no probs anymore with it.