I had been playing with which way to orient the stone it since I got back - vertical, horizontal, around and around but it had horizontal BECAUSE of the scene.
Then, because of the translucent nature of the agate, the bezel setting is opened backed. And to further aid in light getting behind the stone, connection between the bezel and the shank is formed such that it raises the bezel off the (my hand) .
Here are a few more pictures showing the setting and how the shank was formed such that it raises the setting off of my hand.