It was pretty far south of HPN- both aircraft appeared to be at about the 25,000+ FL, and the smaller aircraft was definitely not commercial-At this point I am leaning towards the previous post about a KC-10 circling the JFK area.
A highly plausible explanation would be a mock refueling exercise. This would explain the proximity of the much smaller trailing aircraft, the duration of the maneuver and how the follower, after about 60-90 seconds slowly dropped back and moved away to the left.
I guess the question that begs asking is why would they be performing this type of exercise over heavily populated areas