As the final additions to the Paintings of the Temple, Af Klint created three grand Altarpieces, evoking an earlier golden era while also looking towards a new one. The paintings resemble an Egyptian temple, built with intuitive intelligence in accordance with the movement of the sun. The 'pyramid' shape is an equilateral triangle divided into rainbow sections, with a row of oval discs running down the center for added stability. Against a black background, a spectrum of highly saturated colors is used, each with symbolic significance in Theosophical and Anthroposophical spiritualist beliefs. The triangle is an ancient symbol that "connects the material and spiritual worlds, pointing towards enlightenment", as described by the Serpentine Pavilion.

According to Af Klint, these works were created through instinct and contain spiritual messages that need to be deciphered. Art critic Adrian Searle suggests that the paintings are "abstractions and diagrams of ideas - not entirely abstract, but rather representations of elements from an unseen world and invisible forces." One possible interpretation is that the triangle represents humanity's ascent towards heaven, which is the ultimate goal of spiritual life. Another interpretation, based on Theosophical theories, is that the paintings depict the descent of spirit into matter and the ascent of matter into spirit. The preface to the catalogue of the Hilma af Klint exhibition at Moderna Museet in Stockholm describes the works as having "remarkable color combinations, monumental formats, and organic shapes that are otherworldly," emphasizing their transcendental nature and the importance of interpreting them as such.