The Supreme Court of Canada on advertising to children

In summary, the rulemaking record establishes that the specific cognitive abilities of young children lead to their inability to fully understand child-oriented television advertising, even if they grasp some aspects of it. They place indiscriminate trust in the selling message. They do not correctly perceive persuasive bias in advertising, and their life experience is insufficient to help them counter-argue. Finally, the content, placement and various techniques used in child-oriented television commercials attract children and enhance the advertising and the product. As a result, children are not able to evaluate adequately child-oriented advertising.

...advertising directed at young children is per se manipulative. Such advertising aims to promote products by convincing those who will always believe.

Irwin toy ltd. v. Quebec (Attorney general), [1989] 1 S.C.R. 927

scc.lexum.org/en/1989/1989scr1-927/1989scr1-927.html