A content warning for “best faces” would be a statement that alerts the audience to the fact that the content may contain images or descriptions of faces that could be disturbing or upsetting to some viewers. This could include images of violence, gore, or other graphic content.
Content warnings are important because they give viewers the opportunity to make an informed decision about whether or not they want to view the content. They can also help to protect viewers from being exposed to content that could be harmful or triggering. In the case of “best faces,” a content warning would be especially important for viewers who are sensitive to images of violence or gore.