Come on man.
We all know Xiden is not in the White House. So it's seems plausible the weather you saw is from somewhere else, maybe at the fake White House.
We also know the press only wear masks in front of the camera, only for optics. So that moment they were rushing and forgot about it.
Why no statement from the White House that everything is okay?
There were several posts earlier today saying Biden was going to the hospital and they showed a video showing the press running to get a briefing at the White House. The video was daytime, however, the time of the various posts were during the night, if I remember, maybe around 2 or 3 am. Besides that, Biden was at camp David and not the White House.