Replicas and models recur throughout the story, emphasizing how difficult it is to know what is true and what is false. Daniel Leblanc builds small models of neighborhoods and towns in order to give Marie-Laure as much independence as possible. These cunning and perfect replicas are not designed to fool anyone, and they give Marie-Laure the opportunity to “see” more accurately and clearly. Because she memorizes using her sense of touch, these replicas tell her the truth about the space she will have to navigate. However, the replicas of the diamond function to deceive rather than provide accurate information. They make it hard to determine what is real and what is fake, reflecting the way lies and propaganda can be circulated during wartime. While the replicas of the town were originally designed to provide truth, they also become part of lying and concealing because they include hidden compartments where things, such as the diamond, can be hidden. In the end, truth and falsehood blur together and become difficult to distinguish.
The motif of secrets reveals that individuals always have memories and thoughts locked away in their hearts. While working as a locksmith in Paris and raising his daughter alone, Daniel Leblanc hides his doubts and sadness in order to protect Marie-Laure and give her a happy childhood. He also hides the presence of the diamond from her once they get to Saint-Malo because he does not want her to be at risk, or afraid of the curse associated with the diamond. Marie-Laure keeps the secret of Etienne’s hidden radio transmitter for years, and after Werner comes to Saint-Malo, he hides the secret that he can hear an illicit radio transmission. Even von Rumpel hides the fact that he is dying of cancer because he is determined to complete his mission. After the war, many characters carry secrets with them about their pasts. Marie-Laure does not tell anyone about the young German soldier who helped her escape, or what she did with the diamond. This motif highlights how individuals hide not only physical items but also feelings and past experiences.
Throughout the novel, radios reveal the timeless human desire for communication and connection. Radios allow people in one location to be heard in other locations, and this reflects how people who may never meet can still impact each other’s lives. When Etienne is devastated after the loss of his brother, he continues to broadcast the programs they recorded together because he wonders if his brother might somehow be able to hear them. Even though Etienne knows his brother is gone, he cannot help reaching out to try and feel a connection to him. Unbeknownst to Etienne, the broadcasts reach Werner, and he carries the comforting memories of these broadcasts with him through much pain and loss. Even when Werner feels most alone, the sound of the mysterious Frenchman’s voice gives him a sense of purpose and community. When Marie-Laure is trapped in the attic, she broadcasts herself reading out loud because she needs to know that she is not totally alone in the world. This use of the radio ends up creating real connection because it leads to Werner finding and rescuing her.