The statement 'Sweet victory #RingTheBell' accompanied by an image of a baseball game where the Phillies team is celebrating a win does not constitute public discourse. It is a celebratory remark related to a sports event, specifically a baseball game, and does not engage in any substantive discussion on public issues, policies, or societal concerns. The content is focused on celebrating a team's victory in a sports match, which is a common form of expression in sports-related communications but does not address or contribute to civic dialogue on broader public matters.