The Mezzano, in Venetian, is somebody who makes the contact among two parties.
What we see here is the Tracagnino mask ...
... hey … it looks like Harlequin!
... and he also has a batocio!
The Mezzano, with a mechanical extendable device, usually operated to leave messages on the window sills of loved ones, his or somebody else's avoiding to be caught by the lady's parents ... or would leave messages on the window sills of merchants who would rather not let their business known from authorities.
The pantograph machine he is using could be hidden very rapidly and easily.
Most Mezzanos used the Tracagnino mask for their impersonation. Tracagnino is from Romagna, and holds quite a resemblance (and very likely a connection) with the Trachalion of Plautus (Rome, II century B.C.).
In the background we can see two Commedia dell'Arte masks: Zane (a Zanni I would say) and Piatello, the guy with the beard.
This method of communication was also used to pass around messages about smuggling goods in or out of Venice, let’s not forget that Venice has always been a very strong center of legal and illegal commerce.
