Complex sentence: This baroque painting--with a diagonal cascade of mourners and cadaver-bearers descending to the limp, dead Christ and the bare stone--is not a moment of transfiguration, but of mourning.
Split into simpler sentences: This baroque painting, with a diagonal cascade of mourners and cadaver-bearers sliding downward to the dead, limp Christ and bare stone. This is not a moment of transfiguration, but of mourning.