In the Austrian monarchical tradition, the Emperor would wash the feet of twelve of Vienna’s poorest in the Hofburg palace. In the ceremony—separate from the day's Mass—the paupers would sit on a dais. The Emperor would also serve them a meal, and archdukes would take away the dishes.
The accompanying illustration was made around 1910, when Franz Joseph was nearly eighty. His nephew Franz Ferdinand, heir to the throne, is in the foreground, wearing the light-blue hussar jacket.
Here is another post on the pageantry of Austria-Hungary, about the coronation of Emperor Charles I in 1916.
Also, while browsing Getty Images prints from the old Danubian Monarchy, I ran into the one below, which is related to my blog entry on Franz Joseph’s reign from the centenary of his death last November. That article is here.