"This will certainly be controversial among some parents, particularly religious parents of different faiths, and maybe even those who aren't religious who think this isn't appropriate for young children, who may not understand," said Doretta Wilson from the Canadian group Society for Quality Education. She suggested that the Toronto school district was going overboard in its quest to be politically correct.
Canada legalized same-sex marriage in July 2005, the first country in the Americas to do so. Polygamy, however, is still considered a criminal offense.
The Toronto District School Board has tried to defend its decision to put up the poster, and has stated that the image of the three stick figures grouped together does not actually represent polygamy.
"The images in question were meant to support an individual's right to choose whom they love, regardless of gender," Ryan Bird, spokesman for the board said, according to local media.
"For example, the reason for depicting two women and one man was meant to show that a person can be attracted to more than one gender," Bird added.
Bird noted that the goal of the posters was to "identify safe, welcoming and inclusive school spaces for all students."
Several other gender-equality posters have also been making the rounds at Toronto's schools, including one of various multicolored fishes with the message: "We're here, we're queer, we're in your school!" Another poster shows young children of both genders acting in multi-gendered roles – such as a boy wearing an orange wig and stockings and a girl playing with toy cars. "There are No Rules for being a Boy or a Girl," the poster's message reads.
Some comments on the posters, however, have said that the three-person image in particular would be too confusing for students and may have a harmful effect.
"But by being so stupid and so blind how the image reads to most people, the Toronto School Board appears to be promoting a practice that leads almost invariably not only to the sexual exploitation of girls, the expulsion of boys, but poor educational and health outcomes," Canadian newspaper writer Daphne Bramham noted.
"At very least it needs to recall all of the posters and stickers that have been distributed and take it off its own website," she added.
Canada's Education Minister Laurel Broten has also said that while the province of Ontario fully supports gender-based violence prevention programs, the Toronto school board created the posters on its own and they are the result of the board's own initiative.
Annie Kidder, executive director of parent-led advocacy group People for Education, agreed that the main focus of the posters should be teaching that all people are different.
"What the posters are promoting is tolerance… It's a conversation kids need to have, parents need to have. All of us need to be able to wrestle with these things [and] every single kid should feel safe and accepted at school," Kidder noted.