Despite getting absolutely rolled on by two tons of bear, the mirror Steven manages to not expire, because Steven is apparently pretty difficult to kill these days. It's a lot less happy with its life, though, and due to the fact that its claws were just not long enough to make it through all that polar bear fat with a slashing motion, and it realizes it needs to change its tactics.

So as Lapis turns on the original clone, who is still fighting off a cascade of water clones with increasing levels of fervor, it sharpens the ends of its fingers and causes its arm to explosively grow, causing its claws to shoot at Lapis's back like a spear. If it can't cut, it'll stab.

Sufficiently distracted, the mirror clone fighting the water clones gets smacked across the face with all of Lapis's bear power, knocking the clone to the ground and shattering it. Real Steven would have just passed out at this point, but it seems the clones have no use for being unconscious.

Yet, as Lapis goes for the tree, its the perfect opportunity for the other Steven to strike.