Dr. Ed (Mazza) sent me another message with MORE details on Pope Innocent’s image and it is fascinating!
“And here’s more on Innocent’s image:
Behind the altar, in the apse of the old Basilica of St. Peter was a mosaic portraying Innocent III as the bridegroom of the Roman church. This stylized picture placed that marriage at the center of salvation history. In the forefront of the picture is Christ, the Lamb of God as described in Revelation :. On one side of Christ, Innocent III, barefoot and wearing a crown, stands facing his bride, the church, who is portrayed as a beautiful woman. At the edges of the picture are the two cities, Bethlehem and Jerusalem, scenes of Christ’s birth, death, and resurrection. Above these the figures of St. Peter and St. Paul preside, while the four rivers of Paradise pour down around the Lamb. Over all is the hand of God the Father, while in a corner Adam and Eve symbolize death coming into the world.1 This representation illustrates the message of Innocent’s sermon for the first anniversary of his coronation…
He and the popes who followed him were to be joined to the church by marriage bonds that were indissoluble. The memorial of the nuptial was the mosaic in Peter’s own basilica where the inscription beneath the picture proclaimed: This is the supreme See of Peter, the beautiful and splendid Mother of all the churches, which is the sacred temple of the High Priest. May the one designated by Christ, whom he serves in this very temple, receive the flowers of virtues and the fruits of salvation”.
 Vause and Gardiner, Between God and Man, p. 32.