In a traditional Roman apsidal mosaic, the frieze under the figures of Christ and the saints normally depicts a row of sheep, symbolizing the apostles, looking towards the Lamb of God. However, in this mosaic, which marks the first major work in a new phase of Byzantine-inspired church decoration in Rome, there is a row of apostles, saints, and archangels. The basilica is famous for its mosaic medallions of all the popes. However, what is especially beautiful and rather moving is a tiny mosaic figure of Pope Honorius III clinging to the foot of the Lord in this apsidal mosaic.
It's not clear, of course, how much of these details concerning the vesture of Honorius III actually reflects what he wore in the early 13th-century. Mgr Guido Marini notes that the "long pallium crossed over the shoulder was not worn in the West as from the 9th century onwards. Indeed, the painting in the Sacred Cave of Subiaco, dating back to ca. 1219 and representing Pope Innocent III with this type of pallium, seems to be a deliberate archaism". So, perhaps the same archaising tendency is evinced here in this portrait of Pope Honorius III? Nevertheless, it is a beautiful detail that shows the richness of material and noble form of ancient vestments, and it appears to be a style with which that reigning pontiff wanted to associate himself.
Click the image of Pope Honorius III above to enlarge it.