I can't remember where I read this but when you're rear seats are too upright then the arm rest looks like it's flopping down but when your rear seats are reclined in the normal position then the arm rest is more elevated. In other words the angle of the arm rest is tied to the angle of the seats.
The arm rest is level when the rear seats are reclining in their proper position. It only has 1 stopping point so if the seat backs are foreword, the armrest appears to have a tilt.
Hmm. That's not a great design. My seats are fairly upright to a) accommodate child seats, and b) maximize cargo area shape & size. Thanks @Sam_K and @rconkling
The armrest should be level when the rear seat is in its "full back" position. When the rear seats are adjusted froward the armrest starts to angle forward\downward. Please look at the pictures I took. So if the armrest is flopping forward/down with the seat in full back position...there is something wrong with the armrest.