The 34-year-old Mumford & Sons rocker appears to have taken the Oscars-themed lampshade that was sitting on their table at the event.
Marcus is seen holding the lampshade in his hands while riding in a van after the show. He also documented some other moments from the night, including how he used Chanel eyepatches to prepare for the show.
You can check out all of the photos on Marcus‘ Instagram page.
Carey was nominated for Best Actress for her work in the movie Promising Young Woman, though the award went to Frances McDormand for Nomadland.