From the camera position, mounted uniformed men can be seen approaching. They are identified as Vatican guards. A company of foot guards in full regalia and carrying spears follow the mounted guards.

Source: Library of Congress

Sectarian suspicions were rife in late-Victorian England, which made the marketing of films featuring Pope Leo XIII something of a chancy proposition. Nevertheless, it's hard to argue that contemporary audiences disliked parades. This procession - courtesy of the Catholic Church - fits firmly within the early film tradition of filming pomp and circumstance. It's possible that reactions at home were not foremost in Dickson's mind.

The filming in Rome went on long enough that some of the films were shipped to England for developing and back again, in time for the Pope himself - the first ever to be committed to celluloid - to see. Is this one of the films that were shown to the Pontiff?

Source: BFI