The co-existence on this altarpiece of such unrelated episodes as the Last Supper, Pentecost and the Assumption Into Heaven/Coronation of the Virgin all contribute towards making this particular altarpiece a truly peculiar one inasmuch as it may be interpreted in several different ways such as the Glorification of Mary and the Exaltation of the Eucharist.
As indicated by Professor Périer d’Ieteren in the study carried out during the most recent renovation work, the answer might well reside in the identification of these themes with the kind of worship imparted by Trinitarians and Augustinians, a hypothesis ratified by the important presence of the Holy Spirit in the two scenes in which the Virgin Mary is present. In this sense, we should remember that it was precisely during the Last Supper when Christ announced the imminent arrival of the Holy Spirit to His Apostles.
Bearing in mind that the vast majority of the reliefs are missing, the explanation for the way the compartments of the vertical registers of the altarpiece are subdivided is less clear. However, they could have held a series of iconographic representations of a Holy Bishop.