Can you say no-brainer? Even though the story is fictional, Yelchin's novel gives us a glimpse into what life was really like during one particular historical moment (the 1950s) in a real-life place (the Soviet Union under Joseph Stalin). If you haven't checked out the "Setting" section yet, why don't you go ahead and do so now, since you'll find lots of helpful 411 on the basic situation in Moscow during this time.
Sure, Sasha doesn't completely grow up in this book (he's only ten years old, after all, and the novel takes place over the course of a mere two days), but he does make some pretty big strides in that direction. Even though he doesn't yet make it past adolescence, what happens to Sasha is huge, and he learns some harsh lessons. By the end of the book, he's moved away from his childish idealism and learns to question things more and not just blindly accept what the system tells him.
When a smartly-dressed talking nose interrupts an otherwise totes realistic narrative, we have one major clue that we've entered magical realism territory.
Sasha's running down his school hallway, trying to evade the senior lieutenant who is going to hustle him off to the dreaded orphanage, when suddenly he comes face to… well... nose with Stalin's nose. The nose tries to get Sasha to denounce his father as an enemy of the people, and then takes the opportunity to recount what he considers a real knee-slapper of a tale about how he once falsely accused some workers of stealing his pipe. A clue: it didn't turn out well at all for the workers (25.15).
But wait a second. What about Sasha's rather overactive imagination? Doesn't that account for this strange conversation with his new nasally acquaintance? Well, not quite. Keep in mind that in all other instances when Sasha lets his imagination run wild, none of the actions actually happen. So, when he's imagining being at the May Day parade, tanks don't really come rolling into the deserted hall.
Here, though, Stalin's nose apparently does really speak to Sasha. Pretty weird, huh? What do you think this adds to the narrative? What's the author trying to do by giving us this delightful little moment of utter surreality?