 The relief, "St Catherine in Ecstasy", shows the saint in a very indeterminate stance on a cloud pushed by an angel and some putti, all in white marble (some of the flattest parts of the cloud are in plaster).The scene is embedded in an smooth, polychrome background which forms a concave curve through which it underlines the protagonist's statuesque appearance, seemingly detached from it.Its pieces of differently coloured marble are arranged in such a way that they suggest dematerialised dark clouds opening up to let St. Catherine ascend to heaven.