Apparently it was supposed to be the white and red stripes of the US flag, and Biden just so happened to stand in front of the red part. That's probably the real explanation, but why are there marines standing behind him in frame like that? Why did he have both of his clenched fists raised? Why did his Twitter account (his office's account really, probably run by a staffer) just tweet the single word "democracy" (not even any quotes in the tweet, just one wholly lowercase word) at about the same time? With the whole "Dark Brandon" meme going around at the same time (originating from some Chinese propaganda trying to make Biden look bad, but glowing yellow eyes and a throne made from M16 rifles isn't going to make you look too bad in the US at this point), the coincidence is a bit weird.