The imposing order of Corinthian pilasters that rings the entire interior, the theatrical focus on the high altar at the rear of the broad eastern apse, the church's colored marbles, animated stucco figural relief, richly ornamented altars, extensive gilding, and bold Tromp l'oeil (optical illusion) paintings in the 'dome' at its crossing and in the nave ceiling all produce a festive, sumptuous effect.