cazalea[Seiko Moderator]
20790
"a new case shape with refined angles and an elegant sense of proportion; designed to emphasize dials while offering a slimmer appearance on the wrist"
Look at it this way -- obviously the styling over-rules the dimensions, making the watches APPEAR slim while remaining SUBSTANTIAL.
The fatness comes from stacking 4 hands one above the other, and mounting the dials very carefully to avoid cracking or damage in assembly and use.
Putting a spin on it, best I can