Look at the pictures of the "S", on the lower left hand side of the grip, there is a button.

That's the slide release. It isn't by the trigger as we've become accustomed to, it isn't inside the magwell like we used to see in older pistols.

For a right-handed shooter, it's not hard to maintain complete grip control with your right hand, thumb the release and catch the mag with your left, and do a swap. You might need to extend your right pinky, depending on the size of your hand. But for a lefty, it's a big hassle, and you have to completely reset your grip in a swap.