The song opens with a powerful metaphor, likening emotional pain to a 'shotgun to the back of my heart.' This imagery sets the tone for the entire piece, suggesting a sudden and violent betrayal that leaves the speaker reeling. The line captures the essence of heartbreak, where the pain is both unexpected and deeply felt. The phrase 'I don't turn around to see who let one ring out' implies a refusal to confront the source of this pain, perhaps indicating a desire to avoid further hurt or a sense of helplessness in the face of betrayal.

As the song progresses, SZA introduces themes of violence and loss, referencing a 'massacre' and the haunting consequences of her past actions. The line 'Killed a small boy once, never told no one' serves as a stark metaphor for guilt and the weight of unconfessed sins. This imagery evokes a sense of remorse and the burden of carrying secrets that can never be shared. It reflects the internal struggle of reconciling one's actions with their identity, a central theme throughout the song.

The repeated questioning in the chorus, 'Am I all that I pretend to be? / I doubt it, I doubt it,' highlights a profound sense of self-doubt and existential crisis. SZA grapples with her authenticity, suggesting that the persona she presents to the world may not align with her true self. This introspection is a common thread in her music, where she often explores the complexities of identity and the pressures of societal expectations.

The mood of the song is somber and reflective, capturing the emotional turmoil that accompanies heartbreak and regret. The metaphor of the 'Green Mile' serves as a powerful backdrop, representing the finality of life and the emotional toll of facing one's past. The outro, filled with self-doubt, reinforces the idea that the journey of self-discovery is fraught with pain and uncertainty. Overall, "Green Mile" is a deeply introspective piece that resonates with anyone who has faced the consequences of their actions and the struggle to find peace within themselves.

Released in 2014, "Green Mile" reflects a period in SZA's career where she was beginning to establish her voice in the R&B genre. The song's title draws from the cultural reference to the last walk of death row inmates, a concept that resonates with themes of mortality and the weight of past actions. This context adds a layer of depth to the song, as it not only speaks to personal struggles but also touches on broader societal issues surrounding justice and punishment. The song's release coincided with a growing interest in artists who blend personal narratives with social commentary, making it relevant in discussions about mental health and emotional well-being.