This is not really a mask, but more like a "lurid popular caricature", what was called in Venice at the time, a "maschera barona" (a plebeian mask), that went on in Venice for quite some time in the XVIII century.
Bernardon was this old guy all bandaged up, with scars and sores, stopping at the café tables where people were spending their time, asking for money.
He pretended to be affected by the "French Disease" (syphilis) for having had exaggerated sex experiences without any restraint.
Bernardon is taken around in his wheelbarrow, sings foul songs and begs for money, with a bandaged head and a body full of fake sores.
"Povero Bernardon tuto impiagao!
Col baston son redoto, e pien de fame,
a pianzar per la strada el mio pecao
che tuto intiero m’à imarzio el corbame;
causa ste scarabazze, e la so scuola,
so sta butao ne la quinta cariola."
"Poor Bernardon, full of sores!
I can't walk without a stick, and I'm full of hunger,
here I am crying about my sin
that has completely damaged my skeleton;
because of these women of sin, all of them,
I have been thrown sick in this deep misery."
The wheelbarrow may be a physical representation of the idea of "quinta cariola", being the cariola how the wheelbarrow is called in Venetian, so it becomes a word joke inside the tease. But this is my interpretation.
Some historians see in Bernardon a disguise set up by the government to moralize Carnival: not sure if it worked as it was supposed, though.
How the St. Mark's Square would have looked back then: the painting here on the right may well represent the kind of situation/people in St. Mark's Square in the XVII or XVIII century.
Here the "Bernardons" would go around bragging, lamenting and asking for money, with their fake open sores ...
In any case, the Bernardon disguise was banned in 1815 by the second Austrian Government, and that was the end of it.
