Maybe the video was recorded going forward and played backwards?
That’s impressive given MH has such long rear overhang.
My father could back up wagons on the farm a long distance. He said it just took practice. I tried it a few times and could go a little distance but only if fairly straight. Compared to a dolly, it was helpful that wagons had long tongues and his pickup a short rear overhang. Wagon wheelbase was longer than that of a car, which also helped. Using a tractor made it a little easier than a pickup. There’re a lot of variables that may help or make it more difficult. Skill is essential in any case.
Cool video.