Many of Álvarez's works were grouped into specific themes, which she returned to time and again. They included representations of indigenous and peasant women, mothers, children, women of varying social classes as well as the women involved as avant-garde participants in the Mexican muralism and intellectual renaissance movement of the interwar period. Besides the images of her friend Frida Kahlo, for whom she was known internationally later in her career, are portraits of artists, such as Lilia Carrillo, Olga Costa, Marion Greenwood, María Izquierdo, Alice Rahon, and Cordelia Urueta; cultural preservationists, including Pita Amor, Anita Brenner, and Judith Martínez Ortega; and writers, such as Rosario Castellanos, and Elena Poniatowska. She also created a series of nude portraits, which were unique in their depiction of women as "alegorías de la condición femenina en el contexto de la sociedad patriarchal mexicana (allegories of the female condition in the context of Mexican patriarchal society)". These included her nude image of the dancer Maudelle Bass, and the heavily-pregnant artist Julia López. Her contemporary male photographers, when depicting motherhood, captured more traditionally domestic images. Her street photography focused on people's daily lives as she strove to expose beauty, as well as the misery, and the irony of the human condition. Her work displayed an instant in time and did not have any symbolic or underlying meaning but instead was a way of preserving a moment in life.