The Mimic might be immobilized, but Naoto needed to move and quickly reload. Also, with the ice, she decided Ifrit couldn't risk melting it free and the ghostly beast shifts, becoming more serpentine as Leviathan materializes.

With a fresh clip, Concentrate is passively activated as Naoto took the next shot from the front at the Ancient Mimic - hopefully with the elemental coat still on - again going for the mouth while Snow White attacks from behind. Following the single bullet shot, Leviathan would douse it with Tidal Splash.