If you watch the whole clip as they approach the podium, you'll notice that both Hunter and Ashley Biden step up and forward onto a platform and that the girls in pink and white are actually farther back than they appear on the front-facing camera. When the angle switches over to the side profile, they disappear because they are out of frame. I initially glossed over this theory because NTD and Real America's Voice both did livestreams, but then I started to believe that it may have been pre-recorded due to the disappearing act. I also thought all the news streams were playing the same clip, but after examining the NTD and WSJ streams closely, it's clear that separate cameras were used from a similar angle but positioned at different heights.