There is an imitation of the Pietas in St. Gios showing the BVM standing and also a 14th century mosaic.
The third picture shows the priests and choir performing Sundays mass (we visited on a Sunday).
The fourth picture shows a chapel which is common in these large cathedrals. This one was sponsored by a dominant family of Italy, I think the one after which the cathedral itself is named.
The final picture is of the floor. Part of the floor was commissioned by the 15th century pope who ended the great schism. It reminds me of q-Bert. Or Escher.