Tarkovsky and Konchalovsky met each other in 1960. They wrote the script for ANDREI RUBLEV together. (Also IVAN'S CHILDHOOD). It seems this film highly influenced Tarkovksy on making ZERKALO (though as a project, ZERKALO's birth date is 1964, similarity in style can be observed easily).
Like in Oliveira's "Benilde ou A Virgem Mãe" and Fassbinder's "Bolwieser", space and light are the drama conductors, and as with his brother's "Unfinished Piece for Mechanical Piano", maybe the most accomplished Tcheckov adaptation for cinema. The carachters are figures that the camera compresses or distributed in space, and light is an artificial eye.
Accomplished Russian film adaptation of Chekov's Uncle Vanya. Woody Allen calls this "the best Vanya" and it may be. Well performed, well filmed, funny. Of course it's Chekov so it sometimes move at a ... stately ... pace. I wouldn't consider it especially slow, though, unless you're conditioned to American action movies and romantic comedies.