photo by Tim Jones
Up at the front of the passenger area of a Venetian gondola,
there is a five-sided piece called a "portela".
It sits vertical against the opening of the bow,
resting on the back edge of the trastolini board that's furthest forward.
Small tabs hold it in place on either side, but the piece is easily lifted out to access the front compartment.
Because this piece is among the most prominent surfaces to the gondola's passengers, gondoliers usually put a lot of thought into what will be displayed on the portela.
Here on this portela, guarded by two gold dragons with dolphins looking on, is a family crest. Another name for this is a "coat of arms".
My guess is that the crest is that of the gondolier's family.