I’ve watched Pokrovskiye Vorota at least twice before, but on my latest watching, toward the end, I detected a fleeting smile from Lyudochka that I was sure I had seen before.  It comes just as she’s about to kiss Lev Khobotov (Anatoli Ravikovich) again.  It’s hard to capture in a screenshot, but it’s a little different from anything else she has done in this film.
After a half-hour of scratching my head, I remembered.   The woman who plays Marta in That Very Munchausen has a smile like that.
And sure enough, it’s the same actress, Yelena Koreneva.  That’s pretty good for her to play those very different characters in very different ways.