The Clinton’s have a lot of Hollywood friends/sycophants and so access to Green-Screen technology is not far-fetched. My favorite part of the “Press Conference” is when she turns around and waves behind her to the crowds, but no one is actually there. She’s so drugged up she can’t even take direction.
The crowd is so immediate off to the side, and her body language appears to be properly oblique to be aiming towards that crowd.