IMHO, this is so simple, it's stupid.
It doesn't matter what signals the pilot and co-pilot work out between each other. As long as they understand each other. After watching the video, I understand what it's trying to portray. Most coming out of their RVs in neighboring sites are coming out to watch the fun. guy in the video is trying to land a 757. And that may work for some. That's fine.
It doesn't have to be that complicated. There are two-ways available that may help with communication between the driver and the spotter. Otherwise, a communication plan between the driver and spotter should be sufficient.
The driver should know what he/she is doing. Either forward or backward.
Newbies are excluded. Everyone has to start some where. I would be one of the first to offer help. But, drivers/pullers should know how to back the RV up into a spot.
If not, it's time for practice in a vacant lot somewhere. Otherwise, expect the audience.