Shinnecock has much flatter bunkers. They are not the pre-eminent feature of the course. They do not have the size nor the definition of Sebonack's bunkers, which are in a class of their own. From what i saw of NGLA from the media shuttle, the NGLA bunkering is similar to the bunkering at Southampton, which should come as no surprise, since both are from the CBM/Raynor camp.
Sebonack's bunkers are maverick affairs; they dominate the abundant landscape.