Hi paulino88,
Koi lines, (family pools, lineages, groupings) carry distinctive characteristics,... and among the more prominent of these characteristics are the shape of the Kois face, and the body shape - the distance between the eyes, the distance from the shoulder (where the scales start) to the tip of the nose, the size of the snout all make up the shape of the Koi's head. Some are long, some are pointed, some are thick and chubby, some will have eyes that are sunken and surrounded by fat, and on and on,... and these characteristics can be grouped into categories, and these "shapes" will often coincide with a particular "line" or lineage,... regardless of the breeder. These characteristics are what allows a breeder to choose and build or breed a Koi with a "look" that he wants to see - and these characteristics allow hobbyists to choose Koi with a look that they enjoy.
This is the classic Yagozen face shape. If you look at the shape of this Kohaku's face and look at the faces of the other Yagozen type Kohakus I posted above you'll see a common facial shape, as well as other distinctive characteristics.
Best Wishes,
Brady Brandwood