Potemkin only realizes he was hanging in anticipation when Ky stops moving. That's when it hits him that he's been standing as if suspended in time, which isn't very conductive for Ky or Potemkin returning to their rooms. Potemkin is about to step to the side to let Ky pass first, but seeing Ky's arm move in the corner of his vision, to the side of his head, makes him stop again.

He has to remember all over again that Ky is this close, that it's this easy for Ky to reach out to him with his glamor on. To reach out, to touch... Potemkin has his restrained behavior even when his strength isn't visible, so he doesn't move an inch despite seeing his hand and giving every bit of Ky's actions an agonizing amount of attention.