It has a context of patronage which gave rise to its inception. Surely this must have a meaning as well. If the artifact possesses an iconic content which reveals meaning, then the act of patronage must be, therefore, an iconic act, and will reveal some meaning as well. In the example of Pope Sixtus, the iconic act of patronage is much more interesting than the particular content, for it evokes the central Mysteries of the Catholic faith. The iconography is so internally coherent and so complete as to suggest that patronage is not an accretion to his ecclesiastical authority as it is an unfolding of that authority, a position which the pope rightly holds.
Patronage is a liturgical act.
The iconography of patronage which is concentrated to a brilliant point in the Holy Father himself is also writ large on the Christian polity. When the church acts as patron to the social order, doctrinal truth and ecclesiastical authority become the pattern for the law and judiciary of the civic culture. When the Church gives of Herself completely and becomes the patron to the world, she becomes written on the society at large. Patronage is the way that the truth of the church is transmitted to culture. The church is magnified through the secular culture, and the secular culture flourishes.