Well, clear back in TDTCB in the first dream we ever see, Akka sees his self in the mirror instead of Seswatha. And, while he notes there are discrepancies in the Dreams, that he'd never experienced or heard of something like that (in the Slog of Slog thread I quote it and there is discussion on it).
From the Bakker thread he made at Westeros, someone suggested when Kellhus spoke to Seswatha in TWP to gain access to the Gnosis, that maybe he might be manipulating the Dreams, Bakker gave a wink emoji. Which if that is the case, would be disappointing. I don't like that Kellhus and no one else is involved in these events. I want something to be outside his control. But, oh well, it is what it is.