This is the first frame of the film, more or less:
Andrei Rublev is the Man Without Qualities of film: highly regarded, vast and inaccessible (also the Russia of films?), and inspiring fanatical devotion among those who make it all the way through — perhaps they want to convince themselves that they haven’t wasted the time in which they could have watched three of Godard’s films. Some fans even up the ante and claim that the film is impossible to understand unless you’ve seen it four or five times, preferably in succession, without sleeping, on a stone floor, with only an Old Church Slavonic prayer-book for company.
This still adequately represents the film as a whole, both its aesthetic qualities and its plot. If you want to know what this vaguely menacing sack actually is, you’ll have to watch the film. Or at least the first five minutes.