I prefer the p tag to be empty, and to have a class name that is targeted by the constructor for toaster instead of just targeting the p tag. Otherwise, the p tag looks like an accident. 

Longer term, I want to use the web componenty experiment I did where we use data-bind attributes instead, which would make this clearer, but for now, let's stick with what is code practice now: specific CSS classes that are targeted for binding in the widget's constructor.