Blondie -
Leo dealt brilliantly with the what will be the sign of "your coming" versus "presence" quite recently, and showed that in the greek of the time they meant exactly the same thing in this context.
Rather like we say "when will you arrive" "when will you get here" "turn up" "come" "show up". Like any LIVING language, the people speaking it have many ways of saying the same thing.
The NWT is less accurate in that it stubbornly insists that parousia only means ONE THING and that is what the Witchtower has decreed it to mean : INVISIBLE PRESENCE that ONLY they know about.
HB