It's possible the artistic shot used a real image as a model, the stars added later for effect. I can even see a faint milky way effect added to the background, which certainly would not be seen with an image processed to show detail in the glare of sunlit Saturn. As for the lack of penumbral shadows, viewed from Saturn's distance, the sun is almost a point source of light, there would be only a tiny penumbra. The shape of the shadow of the rings would depend on the sun-planet-ring geometry. I don't know the exact figure, but I thing the angle can vary by about 30 degrees on either side of dead-on throught the Earth-Saturn synodic year.

The hexagon in the artistic rendering may very well be real and have been brought out by the processing but the analyst ignored it or even failed to notice it. I doubt if I would have seen it if it wasn't pointed out.

Hexagons of this type, by the way, are often seen in satellite images of earth's clouds, which often break up into six-sided polygonal "Hadley Cells", they're convective features of some sort. The hexagonal geometry is related to a minimum-stress configuration, like you sometimes get in drying, cracking mud flats, hexagonal basalt columns such as the Devil's Causeway in Ireland, or even in insect hives.

I find it flabbergasting that people can ignore a show like this and spend there time worrying about UFOs or the Bermuda Triangle. The real world is just so much more profound and marvelous than our wildest fantasies about it, and that little robotic spacecraft out there, dancing its Newtonian dance in that cloud of worldlets, is a human accomplishment and achievement worthy of the natural beauty it is revealing to us. It is a triumph of the human intellect and I am really honored to be a member of the species that sent it there.