The Palais Garnier represents the Beaux Arts style as it is symmetric with arcuation, and a heavy use of sculptural elements. Comparing this to the San Carlo alle Quattro Fontane of the Baroque style, you can see there is more curvature with he Baroque building, although still a symmetric face. The roof of the baroque building is also more irregular than the Palais Garnier. Both buildings feature the oeil-de-boeuf windows, being a significant feature in both the Baroque and Beaux Arts. The Palais Garnier actually has quite dramatic and ornamented features, which is typical of the Baroque although the San Carlo alle Quattro Fontane has a lot more white on the interior and brings its drama and intricate focus on the ceilings and religious figures as it is a church. The Palais Garnier is a secular building, and you see the more modern ornamentation all throughout, including grand staircases with iron framework.