In the first spans of the main nave in the middle of the vault the keystone bears a prophet: here there is only a white cross on a red background. It is the coat of arms of the Municipality of Como, a way to recognize that the Cathedral is also the Duomo, the common home of citizens.
The banner exhibited in the display case on the northern side was placed there in 2017 as part of the rearrangement of the tourist route inside the Cathedral.
On this side Christ is depicted crucified between Mary and John the Evangelist, partially hidden by the group of lay people, confreres and sisters of the Confraternity of St. Abbondio, kneeling and praying, at the same level as Magdalen who embraces the cross.
Note how the group of male portraits agrees with St. John, the female one with Mary, who is in the canonical position, to the right of Christ. On the other face of the banner the male group takes on the usual privileged position, to the right of St. Abbondio.
The banner was painted in the second decade of the 16th century. The display case was designed by architect Federico Frigerio in 1901.
It seems that the paintings of the vault of Gabetta and Fontana (1839) were thought of as a corollary of the Como coat of arms:
St. Faustina nun St. Liberata nun
St. Andrea Avellino priest St. Giovanni Nepomuceno
St. Pietro Martyr S. Lucia virgin and martyr
St. Proto martyr St. Giacinto martyr