When Roca (Armando Moreno) goes to the cinema, some of the posters that are hung on the walls are from films made by the IFI production company, the same one that produced "Cuatro en la Frontera". In addition, the one that is left behind belongs to the film "El ojo de cristal" (1956) that was directed by Antonio Santillán and starring Armando Moreno himself.