In this artwork, how is the Small scenes of the Iconography elucidated?
It is common in Early Netherlandish painting to have small religious scenes shown as sculpted reliefs in the background, to increase the depth of religious reference.  But the choices of the four small scenes shown on the pillar and architrave just behind the main group, and above Mary and Jesus, are unusual in painting.  On the architrave, with a red background, the left side has been identified as starting with the obscure and uncommon scene from 2 Samuel 23:15–18 of King David, when Bethlehem was held by the Philistines, refusing to drink the water that three men had drawn from a well at great risk to themselves:
15 David longed for water and said, "Oh, that someone would get me a drink of water from the well near the gate of Bethlehem!" 16 So the three mighty warriors broke through the Philistine lines, drew water from the well near the gate of Bethlehem and carried it back to David. But he refused to drink it; instead, he poured it out before the Lord. 17 "Far be it from me, Lord, to do this!" he said. "Is it not the blood of men who went at the risk of their lives?" And David would not drink it. (NIV)
This scene had sometimes been used in art as a typological prefiguration of the Adoration of the Magi, apparently based on the basic similarity of a visual composition of three men offering something to a royal figure regarded as an ancestor of Jesus, rather than any theological relationship. For example, they appear in an altarpiece panel by Conrad Witz, and are carved in the frame of Michael Pacher's St. Wolfgang Altarpiece (St. Wolfgang im Salzkammergut, Austria, 1471–81).
To the right of that, along the beam, is a horizontal version of the much better-known scene of the Tree of Jesse, from Isaiah 11:1–12, which viewers of the period would easily have recognised.  In the medieval Christian view, this illustrated the genealogy of Jesus.On the pillar there is the Tiburtine Sibyl showing Augustus a vision high above them, a well-known Christian legend.  In the versions known to the later Middle Ages the Emperor Augustus asked the sibyl whether he should be worshipped as a god, as the Roman Senate had ordered.  She replied by showing him a vision of a young woman with a baby boy, high in the sky, while a voice from the heavens said "This is the virgin who shall conceive the saviour of the world".  The episode was regarded as a prefiguration of the Magi's visit, and for example is paired with an Adoration of the Magi on the two side-wings of Rogier van der Weyden's Bladelin Altarpiece (1460), now Gemäldegalerie, Berlin.
Below this on the pillar is the dream of the butler (or "cupbearer") from the Old Testament story of Joseph in Genesis 40: 9–15. He sits in the stocks, to represent his imprisoned state, carries Pharaoh's cup, but "oddly" wears a crown himself.
9 So the chief cupbearer told Joseph his dream. He said to him, "In my dream I saw a vine in front of me, 10 and on the vine were three branches. As soon as it budded, it blossomed, and its clusters ripened into grapes. 11 Pharaoh's cup was in my hand, and I took the grapes, squeezed them into Pharaoh's cup and put the cup in his hand."
12 "This is what it means", Joseph said to him. "The three branches are three days. 13 Within three days Pharaoh will lift up your head and restore you to your position, and you will put Pharaoh's cup in his hand, just as you used to do when you were his cupbearer".
A typical medieval interpretation of the prefiguring relationship with the birth of Christ was that "the cup bearer symbolized humanity captive in sin, the vine symbolized Christ who would redeem mankind, and the grape juice prefigured the blood of Christ."All these scenes are found in various versions of the Speculum humanae salvationis, an illustrated handbook of typological pairings, mostly between the Old and New Testaments, which was highly popular in illuminated manuscript, blockbook, and printed forms from the 14th to the early 16th centuries.  Mostaert seems to have used a blockbook edition from some fifty years earlier as the basis of his compositions.Both a scene of Augustus and the Sibyl (in the background at left), and a vine relief pattern on a red background on a pillar appear in Mostaert's Portrait of the Knight Abel van Coustler, probably of a similar date, and a very similar scene and background building are used in a female portrait in the Gemäldegalerie, Berlin.  A small painting of Joseph explaining the dreams of the Baker and Butler, c, 1500, in the Mauritshuis is tentatively attributed to Mostaert.  Each dream is illustrated on the wall above the dreamer.  A Tree of Jesse, hung near the Mostaert Adoration, has a complicated and disputed attribution, according to some scholars involving Mostaert, as well as Geertgen tot Sint Jans, who died in Haarlem in 1495, or his workshop or pupils.
Michael Pacher Genesis Conrad Witz Mostaert Tiburtine Sibyl typological prefiguration Bladelin Altarpiece Bethlehem Gemäldegalerie, Berlin Middle Ages Tree of Jesse Mauritshuis Rogier van der Weyden Sibyl sibyl altarpiece Old Testament Geertgen tot Sint Jans Altarpiece relief genealogy of Jesus David King David blockbook NIV Roman Senate Adoration of the Magi Joseph illuminated manuscript Speculum humanae salvationis architrave New Testament Augustus Philistines Early Netherlandish painting stocks