Tom, I wish that you had looked at the diagram that I furnished. There are two ropes, and that is why it is called the two-rope hang. One rope is used to counterbalance the two food bags, and the second rope is used only to pull down the one food bag so that it is level with the other food bag. The second rope is called the pull-down rope. It is possible to do almost the same thing with a push-up stick, but that gets unwieldy with heavy food bags.
It seems to me that one method might be easier for getting the food hung in the evening, and one method might be easier for getting it down in the morning.
Incidentally, I watched all of this unfold one night when the bears visited. Our group had the food hung sometime well after dark. I wasn't crazy about the way that our leader had hung it, and I thought that the food bags were too close to the tree trunk. So, I had a mini-tent right at the base of the tree. I wasn't in the tent long when I heard claws on the tree trunk, so I came running out with my light. A half-grown bear was already up the tree trunk and was wandering around looking for the correct branch. Unfortunately, the bear had chosen the wrong tree trunk. He was in the wrong one about six feet off. It kept breaking branches and making a fuss, and it wasn't getting the food (as we watched from the ground). It came back to the tree trunk, descended, and ran off into the night. The leader said that he was glad that it was over, but I told him that it wasn't over. We all went back into our tents, but I was staying ready for the next act, so I kept my boots on. Very quickly, I heard more claws on the tree trunk, so I came charging out again. This time it was the little cub brother of the first bear, and he was already up the tree trunk, but again it was the wrong tree. He broke branches and tried to find the food, operating by smell, but he was too far from the food to get to it. The little cub didn't know how to down-climb, so he called for mom. Then we heard the woofing of the mother bear off in the bushes, so we did not want to get between the mother and her cub. We got photos, and all that, and we can see the food bags still hanging. Eventually, the cub descended just a bit and then jumped the rest of the way. Immediately, the mother bear and the half-grown emerged from the woods and all three bears ran off as we chased them. In the morning, our food was still hanging until I got it down, so we started breakfast. Other nearby backpackers came over to ask if we had any extra food. It turned out that the bear family had returned and had hit every other campsite around the lake, and ours was the only place where they did not score any food. Our neighbors got our excess food, but the bears got none of ours.