The Louvre has released a new video clip featuring Lady Gaga, in which she puts a lipstick smile on the "Mona Lisa" to promote the museum's new exhibition, "Figures of the Fool."  The singer channels her Harley Quinn character from the "Joker" movie and sings a specially composed song while creeping through the museum at night.  The Louvre insists that the video is purely fictional and a tribute to Leonardo da Vinci, with additional protective measures in place.  The museum has previously been a playground for stars like Will.i.am, Beyonce, and Jay-Z, who used its iconic artworks in their music videos.