In Jonathan Safran Foer's "Tree of Codes," a poignant moment is captured through a vivid description of an expression that symbolizes loss and fading joy. The phrase "That ghost of a smile fell away and receded and finally faded" conveys a sense of sorrow, as it reflects how fleeting happiness can be and how easily it can disappear from our lives. This imagery underscores the fragility of emotions and the inevitable passage of time.

The use of the word "ghost" suggests something once vibrant that is now merely a memory, implying a connection to longing and nostalgia. As the smile fades, it resonates with the reader's own experiences of witnessing joy diminish, creating a deep and relatable emotional impact. Foer's writing masterfully evokes a sense of melancholy, highlighting the transient nature of happiness and the profound effects of loss on the human spirit.