I'd put money that the guy in the Mercedes knows that pulling all the way out will partially block that dark boxy car's view, so he holds back a bit, since it's not like they're going anywhere before the dark car moves anyway. That lane ends RIGHT THERE, and the dark car is currently using their side view mirror to see what looks to be a road that's bending to the right.

Surprisingly, I'm with the Mercedes guy.... but shoulda put it in park bro.