Hey, is that Count Enrico Pietro Galeazzi?!
No, but this is a gentiluomo/famiglio/cameriere (in this case a knight of four orders) as seen in Rome at FSSP in Urbe (http://roma.fssp.it/).
The gentiluomo is seen here assisting at Pontifical High Mass sung by a cardinal on Dec. 8 of this year.
The gentiluomo walks in procession, stands in the sanctuary, at different times bows to the prelate and washes his hands, etc.
This is a venerable custom of the Church and a fine way to involve the laity.