This action is aimed to make images vivid and sharper than they was before.
On the one hand, Crystal Sharpness is enchancing image itself trying to
imitate the effect of professional lenses (like Canon L-series) improving
gradient colors in light areas of the image (the desease of low-cost lenses).
On the other hand, it makes image sharper giving a photographer possibility
to control sharpness both in light and dark tones thus achieving the perfect
balance of sharpness and total control over it.