https://www.bleepingcomputer.com/news/microsoft/bing-chat-has-a-secret-celebrity-mode-to-impersonate-celebrities/

A secret Bing Chat ‘Celebrity’ mode allows users to instruct the AI to impersonate celebrities, answering questions and talking like the person it imitates.

Microsoft is constantly testing new, hidden features in Bing Chat that allow you to turn it into different chat modes, such as gaming, personal assistant, or a friend who can help you with your problems.