The overall effect of the Cathedra Petri is awe-inspiring; rays of light, made in stucco, jut out from the real source of light. So much emotion is worked into the piece by the expression on the Doctors' faces and the movement of the putti and angels.
Also located on the Cathedra Petri are bas relief of Washing of the Feet and The Handing Over of the Keys to St. Peter, created by Bernini. On the back side is a bas relief regarding Christ's decree to St. Peter, "watch over my flock."
Bernini reduced the size of the Cathedra Petri so that it could be viewed in its entirety through the Baldacchino. In that view, Bernini emphasized the importance of the relics contained in each and the foundation of the Church.