The downward-curved shape of aggressive climbing shoes, concentrating pressure on the toe.
A downturned shoe grips like a claw: the toes are bent downward so all the force lands on a small point — ideal for tiny footholds and overhangs where you actively pull with your feet. The cost is comfort and contact area: on friction slabs and long routes a flat, symmetrical shoe is clearly better because more rubber touches rock. For beginners an aggressive downturn is simply the wrong purchase — it hurts, forces short wearing intervals and papers over missing footwork. Learn flat and comfortable first, specialise later if you need to.