Ah, splendor seen in Catholic culture - let's bring this wonder back to every corner of the world (after all, this is [authentic] lay "participation," right?).
These men lead processions and assist at the lavabo during Pontifical Mass at the throne and altar. They do fine work and add a worthy touch and they bring a lay presence into the holy of holies and they act as role models (heroes) for the youth.
They're knights. In Italy they are called the "gentiluomo" or "famiglio" or "cameriere."