Dog head is an expression in social platforms, which is usually used at the end of comments. Irony is used to emphasize that everything in front of a dog's head is irony. Don't take it seriously, be friendly and don't scold. For example: "This man is really smart, honest and cute", and then add a dog's head to show irony. Because some platforms don't have this expression or users can't send it, they can only use manual dog heads or artificial dog heads (manual funny 23333).