Ruskin perhaps has in mind the conventional renaissance versions of Roman architecture which provide the settings for the main events in Ghirlandaio 's fresco cycles of the Life of St. John the Baptist and the Life of the Virgin commissioned for the Tornabuoni Chapel in Santa Maria Novella, Florence. At Works, 4.323 Ruskin complains that Ghirlandaio 'at last walled himself up among gilded entablatures', and this cycle does represent Ghirladaio's last work, completed to his designs after his death.
Ruskin in Modern Painters I does not seem to be familiar with the St. Francis fresco cycle in the Sassetti Chapel of Santa Trinita Church in Florence, with its representations of Florence, the monastery at Mount La Verna, and a stylised but recognisable townscape of Pisa. Perhaps he would put these passages of architectural painting in the same category as what he calls here 'Memmi's abstract of the Duomo' at Florence.
Later, at Works, 6.10 Ruskin does refer to the depiction of Pisa in the Santa Trinita fresco. There is an illustration facing Works, 6.10, taken from an engraving of 1824 by Lasinio. As Ruskin says, that engraving shows Ghirlandaio to the greatest possible disadvantage.