Again, just trying to apply the principles of photography, a more diffused or spread out light source will show the true colors of the subject.
The second picture uses a direct flash while the first picture used the ceiling and the walls to diffuse the light to have a bigger light source.
Now, let's apply this principle on reef lighting. Spreading the leds will result to more diffused source of light. It will cover every angle with an even intensity of light. This will avoid too many shadows, unless you want that effect.
This is not on the point of view of which configuration is good for the corals but rather what looks good on the eyes of the person looking at the corals.