I think it was art. The island residents have large proportion of artist, writers, photographers etc. People, who work at home, as going to Toronto on ferry boat is very time consuming.
People on the Toronto Island do not own their homes. The land is leased for maximum 100 year. Homes can not be bought or sold. Many are still happy to be able to live there.
The sign here is paraphrasing Woody Guthrie song.