There are so many things to point out in the picture.
A water taxi squeezes between a garbage boat in the process of loading,
and a gondola preparing to board passengers.
The ganzer holds the front end in with his hooked pole,
while the gondolier steps towards the back.
Behind passengers waiting to board the gondola, a conversation takes place between workmen (I believe they're sanitation workers).
Under the roof, gondoliers at the servizio appear to have their hands full with a large tour group, or maybe those folks are waiting (or looking) for the vaporetto.