At the top your hands should stay low, in front of your hips. There should still be tension on the cable, hips should be pushed forward, and arms should be hanging straight or almost pulled thru your hips. Like you would fall forward if you let go.
To get this tension I raise the pulley, from the floor up to around knee height. This way the cable is/moves closer to parallel to the floor. I also take one or two extra steps forward, away from the pulley. I feel lots of hamstrings at the bottom, and glutes at the top this way.
-When I see people pull with their shoulders/arms they are usually really close to the pulley, almost over top of it, and the cable is moving in like a 45 degree angled path. This must be good for something, but I prefer the more horizontal style.