The renowned actor has already collaborated with the Chinese OEM for the marketing campaign of the OnePlus 7 models. Even though the shot is not too detailed, Robert Downey Jr. appears to be holding the upcoming OnePlus 8 Pro flagship that has a newly added camera to the left of the tri-cam setup on the back.
https://www.notebookcheck.net/Leaked-pic-shows-Robert-Downey-Jr-holding-the-OnePlus-8-Pro.457437.0.html