The five green squares on the shield in these arms represent the five parks originally planned for the city, the largest being the central "Queen's Square" (thus, the centre square contains the crown of Queen Charlotte). The supporters are a griffin (taken from the arms of Queen Charlotte's father, who also had a griffin as a supporter) and a silver fox (from the fur industry in P.E.I.). The crest is a ship with the arms as a shield, due to the maritime location of the island.

I apologize for the small image, but I downloaded it from here.