They are not paintings but woden inlays! My astonishment, as I visited this chuch the other day, grew more and more as I explored the choir, right behind the altar. In the XVI century, a monk called Giovanni from Verona executed one of the most outstanding inlay work.
Perspectives of buildings and furniture, allegories and charachters, objects and still-life make a rare example of the kind. (his works are also in the sacristy, about which I posted the day before yesterday). Giorgio Vasari included Giovanni da Verona in his "Vite" (Life of the most eminent painters, sculptors and architects).