Actually, it's just a simple adjustment from an armbar once your opponent has lost their balance and is in a sitting position. A collar choke might be easier to get initially, but it's an entirely different set of steps than this one.
Or a quick way to lock the person back down into a submission if they are able to free their head from your leg during an armbar. Collar chokes are nice, but they wouldn't lead into that type of position.
It doesn't matter if you agree or disagree
... As long as I don't bore you and I spark a moment of thought, my goal is achieved
Queng leon queng tigre ecu tacacut, queca pa? - Pampangan Mandarigma Motto