Although some of these items were left in the secret knothole as gifts for Jem and Scout by Boo Radley, several of them were not. Instead, they appeared in the background of the opening credits of the film version of To Kill a Mockingbird--meant, no doubt, as symbols of the time period. The pocket watch, for example, was "our biggest prize," according to Scout. Jem carried the watch proudly, even though it didn't run; it was a way of emulating Atticus, who also brandished a pocket watch. It also signifies the passage of time. The drawing of the bird (which was not a gift from Boo), symbolizes the title of the story, and the crayon illustrates a child's drawing tool. The harmonica, pearl necklace and whistle were not gifts from Boo, but they seem to represent possessions that a boy and girl might treasure. The soap dolls, probably carved by Boo himself, were representations of Jem and Scout.
The items listed above are depicted in the opening credits of the 1962 film version of To Kill a Mockingbird. Each item symbolically represents an aspect of the aforementioned main characters. The pocket watch symbolically represents Boo Radley's relationship with Jem. Out of all the gifts that Boo Radley gave to the children, Jem's favorite gift was the broken pocket watch. The broken watch also symbolizes Jem and Boo's desire to remain innocent like a child, protected from the community's prejudice.
The drawing of the mockingbird represents the story's main image and symbol. Mockingbirds symbolize innocent beings like Scout, Jem, Boo Radley, and Tom Robinson. At the end of the credits, Scout tears her drawing of the mockingbird, which foreshadows the tragedy near the end of the story.
The crayon, harmonica, marble, whistle, and toys symbolize Jem and Scout's childhood. Each item is something that children use to entertain themselves. The story is essentially about Jem and Scout's progression from their childhood to adolescence. Following the Tom Robinson trial, the children lose their innocence and their perception of the world changes. Fortunately, both children develop into morally upright individuals like their father.
The pearl necklace symbolically represents Scout's future of one day becoming a southern lady. Throughout the novel, Scout is vehemently against assuming the traditional role of females in her society. However, Scout's perception of her future begins to change after she experiences Aunt Alexandra's missionary circle.