I'll let Nick answer fully about the type of modifier (if used) and tech details.
But for Shayne, if you look at the shadow direction and light fall off on the dress, this is an easy example to use to be able to 'read' a lighting setup. This is something that might take a little practice with your own lighting - I can't remember at what point I started to 'get it'.
The flash is high, camera left - directed at the bride, (direction of shadow from the chin) there's a little light on that plant, we can't see much of it (leaf shadows on the dress). I'd guess no modifier - if there was one it was small - judging from the definition of the shadows.
Nice shot Nick.