This campiello is in very close proximity to canal Grande and palace where Gugenhaim art collection is stored [both visible from this spot].
It is quite unusual to see greenery on squares in Venice because space is enormously valuable and mostly reserved for houses. Luxury of green space is reserved only for very rich Venezians.
As in the case of many other little squares in Venezia it doesn't have any significant buildings but it is very nice resting spot in city explorations.