Regarding the Holy Trinity iconography of three equal figures seated with the same suit and age, with crowns on their heads and scepters in their hands, is considered by Pacheco an unclear iconography, since may confuse “the ignorant”. Nevertheless, it is intended to manifest the equality and distinction of the Divine Persons, as well as this image favored in the appearance of the angels in the form of pilgrims to the holy Patriarch Abraham, when, seeing three, he worshiped only one, Pacheco argues this composition needs a particular sign of attribute in which each person is known, as well as the distinction of each character and their places, in which the Holy Spirit has to be in the middle. On the contrary, a model accepted by Pacheco concerning the Holy Trinity representation is the Medieval and Renaissance iconographic model known as the Throne of Grace; also the author accepts the iconography present in the engraving “The Trinity” (1511) made by Albrecht Drer.
“Another painting of this mystery is that one with three figures seated in a suit and age, with crowns on their heads and scepters in their hands, with which it is intended to manifest the equality and distinction of the Divine Persons. And it seems that this image is favored in the appearance of the angels in the form of pilgrims to the holy Patriarch Abraham, when, seeing three, he worshiped only one; and although Fr. Martín de Roa admits it for signifying the Divinity only, it still seems to me that it does not completely satisfy the ignorant, since it needs a particular sign of attribute in which each person is known, and in media, and the place where each one is seated, and the Holy Spirit has to be in the middle.”
“Otra pintura deste misterio es poner tres figuras sentadas con un traje y edad, con coronas en las cabezas y cetros en las manos, con que se pretende manifestar la igualdad y distinción de las Divinas Personas. Y parece que está favorecida esta imagen en la aparición de los ángeles en forma de peregrinos al santo Patriarca Abraham, cuando, viendo tres, adoró uno sólo; y aunque la admite el P. Martín de Roa por sinificar la Divinidad solamente, todavía me parece que no satisface del todo a los ignorantes, pues nececita de particular señal de atributo en que se conosca cada persona, y en medios, y de la colocación de los lugares, y si ha de estar el Espíritu Santo en medio.”
Pacheco 1990, 563, n. 5-6;