The photo above might appeal to some NLM readers, and seemed to me an appropriate image for the Feast of the See of St Peter. Although he is shown enthroned and carrying the keys, he is also surrounded by instruments of his passion and martyrdom:the chains and the inverted cross.
This 19th-century painting is hung in the entrance hall of the Lateran Palace in Rome and seems to have been painted sometime in the pontificate of Pius IX, although rather confusingly, in the full sized painting, the date 1807 appears...
In any case, the pope on the right is Pio Nono, identified by the coat of arms on the stole, as well as his familiar face, of course. Of interest too is the papal formale which he is wearing which is different from the other penitential formale which has featured on the NLM. Click on the image to view the full size.