I always heard that owls swallowed their prey whole and then later will regurgitate a ball (capsule) of the undigestible stuff like bones. I used to work with a woman who had owls nesting in her yard. She would bring in the balls she found at the base of the tree. The swaying looks like a reaction to light then ran in slomo.
They look young and scared. The one next to the one eating appears to be beak clicking which I believe is a warning/distressed action.
They are simply awesome creatures. The more I learn about them the more I love them.