>>32512374The same reason Blaziken does
There's a certain pattern or shape in the design, and it is spread out throughout the entire design and spaced in a way so that the pokemon doesn't feel lacking in detail.
Blaziken has a zigzag pattern on its face, wrists, waist, knees, feet, and crouch.
Reahiram's crouch is to compliment the shape of its feet and the way its feathers stick up on its head, neck, chest, legs, and the ends of its wings and tail.
