At the moment, it seemed maybe the similarities to Killer Frost were limited to Caitlin’s ability to shoot ice from her hands.
But in the episode’s closing seconds, audiences shared in Caitlin’s surprise as she started to be taken over by the villainous personality by way of bluish lips and a light streak in her hair.
First revealed in the episode after Barry got trapped within the mirror world by Mirror Master, Caitlin Snow’s altered Earth-1 identity actually led to Barry escaping, since she finished up the mirror-freezing that the other S.T.A.R. Labs team members were working on.