I can't tell if you both are joking or not but watch the whole video. The source video is of Bill Hader. Bill hader's face changes to Tom Cruise everytime he talks from Tom's perspective. And then once to Seth Rogan for that impersonation.
It probably doesn't help that I am so horrible at celebrities that I couldn't picture Tom Cruise or Bill Hader in my head if I tried, nor do I know what they're famous for. I just know that Tom Cruise sounds familiar and everyone seems to act like Bill Hader is significant so I go along with it.
I guess there's a some change in the face when he switches "voices". It's not nearly as exciting as the one of Obama saying stuff he's never said before though.
Part of the point with fakes like this is it's not just gluing a head on someone else's body, like a bad photoshop. It's actually changing the facial features of the target to resemble someone else.
As an aside, I feel really weird having completely convinced myself that the original video was deepfaked. It's kind of unnerving given the subject matter.