Video Re-centering with background images in use.

What can be done about the video re-centering itself when someone has a background image showing?  If the person on the video moves left or right and you aren't watching on full screen, their image re-centers itself.  Image watching 4 people or 9 people at a time and if they move, their image keeps moving left and right.  It become annoying to watch and distracting during a training session.