Those are the weirdos, the irriverent, the different, not usual figures that have shown up on a Carnival day in Venice, very likely in St Mark's Square.
The uncommon masks, the uncommon situations that repeated themselves during Carnival time, and maybe not.
Ah! c' Cadet là.
Quel pif qu'il à:
Ah! c' Cadet là quel pif.
Ah! that Guy down there.
What a nose he has:
Ah! that Guy down there, what a nose.
The image is referring to the Carnival in Paris, but fits perfectly the idea.