At 45°, the imagery looks quite nice and the rocky areas are clearly delineated.
At 225°, the imagery still looks nice, but now you can also see linear NE-SW trending features in the data. These features could be real, or they could be artifacts in the data. Either way, if I had only rendered the data at 45°, I never would have seen them.
Here is a side-by-side comparison of the two illuminations:
Now that I have seen the linear features in the second view (225°), I can just start to make them out in the first one (45°), but they are still hard to see. By looking at different illumination angles, I can really start to get an idea of features and trends in the data, as well as any artifacts.