"The Transfiguration" by Raphael, circa 1520
Today, Monsignor referred to the transfiguration as a Christophany.
The following is a quote from an article by Father Daniel J. Harrington, S.J., a professor of New Testament at Weston Jesuit School of Theology in Cambridge, Mass.
The transfiguration narrative is about a Christophany, that is, it describes a manifestation or revelation of who Jesus really is. The term Christophany is a variation on the more familiar word theophany, a scene in which God reveals God’s self to humans—as, for example, in the encounter between God and Moses in Exodus 3 and 4. In the transfiguration story Jesus is revealed as a glorious figure superior to Moses and Elijah, and is identified by the heavenly voice as the Son of God. In the Markan context of Jesus’ journey to Jerusalem, the transfiguration gives a glimpse of Jesus’ true nature and the goal to which his journey leads.