full cutting surface (good shape)
The cutting surface has full of flesh, so the cutting edge is tough.
Good for an armour fight.
 
slim cutting surface (poor shape)
The cutting surface is flat, so the cutting edge is delicate.
Good to cut naked person's skin.
 
Be careful, In the window, flat surfaced blades are looking shiny by good reflection.
So a famous polisher removes the flesh from healthy blades to make it aesthetic.
But when you hold such blade in your hands, you will be disappointed with the poor shape.

 
 
KISSAKI
 
KISSAKI is the tip part of the blade.
Its shaping style is very important.
The flesh must be kept from yokote line towards the very tip of the blade. ( YOKOTE = vertical line that distinguishes kissaki from the rest of the blade )

examples of good shaped kissaki
I try to explain shaping with the contour lines.
Please imagine them.

 
 
one example of bad shaping
Do not judge the shape with lines, but please think it with surfaces.
The flesh becomes thinner toward the very tip.

Such shaping is good for display, but if you hold it, you would be disappointed by the kissaki with the poor surface.
Be careful, a famous polisher suggests to repair good surfaced kissaki into the poor one only because it's better in display.