Could be he used the dummy rounds, the ones with the holes in the side, to (safely) show how to chamber a round.
And as has been mentioned one of the rounds laying down looks like the primer is still intact and the round might be live.
Dummy rounds are nice to have around for a lot of different reasons. You can show people the differences between rounds, function test guns and just say "See, that's what a thus-and-such round looks like."