The film portrays a cross-dressing hairdresser whose secret identity is a source of repression and societal suspicion. While the narrative subtly critiques intolerance, the character's experience is one of unrelieved misery, highlighting individuals crushed by conformist demands. The portrayal contributes to a melancholic mood, underscoring the negative impact of societal judgment on non-conforming identities.

Only the River Flows provides a respectful and authentic portrayal of transsexual characters, centering on Sicarú, a transgender woman, within Zapotec indigenous culture. The film explores identity, acceptance, and relationships with emotional depth, framing societal challenges as external while affirming the dignity and complexity of trans lives and love.