My theory is Trump is trolling the deep state suggesting that they've used deep fakes/doubles before. I'm not expert but the reddit post on this said it was a shitty deepfake because Trump had the exact same facial expression (like copy and pasted) in two different frames one in the middle and one at the end of the video. They said something like this wouldn't happen if with the technology the white house has access to. If you guys haven't looked at GhostEzra on twitter I suggest you go there right now and look at his tweets. Could not actually be him but he seems to know a lot. Suggests This Joe Biden isn't the real Joe Biden