The weaver in that film is Feodora Seledkova. According to Kathe Todd-Hooker's "The Russian Old Believers in Woodburn, Oregon," Shuttle Spindle & Dyepot, Winter '96/'97, p. 58-61, a weaver named Feodora S. taught Todd-Hooker how to weave after her tradition and allowed belts to be photographed for illustration. Her age, difficulty finding a successor, and use of a translator are the same in both article and film.
In one illustration, p. 58, there is a piece of wood, with a balled-up knot of completed belt sticking through its centre and a thick belt looped through the notches on either side as though securing it at the waist. The interesting thing is, the piece of wood is shown from the side. You cannot see the clever shape that allows the design to do this.
I think it's interesting that the information would be obscured in the article, and shown in the film.