First there's the fact that Vovka's award-winning painting disappears from its display after his father is executed (13.2).
Then there's the fact that the favorite pastime at Sasha's school involves violently crossing out photographs of those classmates whose parents have been imprisoned or executed as enemies of the people:
Nina Petrovna rises, walks to where the group photograph of our class hangs on the wall, and blackens Four-Eyes' face with her ink pen. That's what we always do to the pictures of enemies of the people, and it usually feels good, but not this time. (22.2)
Check out Yelchin's illustration of this at 22.F1. All traces of these kids are literally removed from the school. Well, not really. You might remember that storage room that the kids aren't allowed to go in:
A faint yellow light flickers from the doorway of some room farther in. It gives off enough light for me to make out the shapes of the things around me. At my feet is Vovka's prize watercolor, Comrade Stalin at the Helm, the colors running in streaks behind the cracked glass. Next, leaning against the wall and buckling in the water, are dozens of group photographs, the kids' and teachers' faces blackened, or stabbed out with something sharp. It's creepy. (28.3)
Keep in mind that the political system of the Soviet Union allows absolutely no dissent. If you speak out, you are imprisoned or worse. What's more, to maintain the illusion that this is the best system and that everyone is happy little communists, any evidence to the contrary must be swiftly, and sometimes brutally, whisked away. "Out of sight, out of mind" (28.4), right?