Tereza walks into Old Town Square, where the old town hall lies in ruins. The people of Prague left the ruined building as a monument to their suffering.
Tereza is reminded of her mother and her perverse need to parade her suffering and personal ugliness.
She feels as though her mother's world is coming back to her. It's becoming a concentration camp, which is what she used to call her mother's world.
In her mind, a concentration camp is "the complete obliteration of privacy" (4.4.3). We are born into a concentration camp and "can escape only with the greatest of efforts" (4.4.3).