While I can see the interest in seeing Ingmar Bergman and Sven Nyqvist behind the camera and at work, there has to be a little more to it than having a second cinematographer run a camera on the crew to make two films (the film and this doc) at once for the price of one. Dokument Fanny och Alexander provides bits and pieces of interesting, valuable material, but is lacking in many respects. It focuses on Bergman and Nyvqist behind the camera, but provides very little insight into the genesis of the story, its meanings, or any of the other crew: nothing on Asp's vision or Vos' work, nothing from the cast about how they approached their work. The doc A Bergman Tapestry, also included in Criterion's Blu-ray, is more valuable and well-rounded in that regard.
As for what we see, it doesn't take long for things to get repetitive. Did we really have to see that clown with the candle on his head *that* many times?