Thanks for that. So it's not a writing mistake.
Then, maybe it's Lacey that's snapped, not the MC, and the reveal is to us the readers, because the MC isn't in that scene...
It could be exactly as you say, the MC was "hearing" things all through out this act, so maybe he heard something completely different than what Lacey said, and he was "seeing" evil Lacey, so yeah, something like a hallucination.
I promised myself I wasn't going to keep analyzing the hell out of this one, so I don't go crazy, too...
Thanks. I remembered
it was fake, just thinking maybe Barty had taken it a step farther, found a girl similar, had her get surgery, or something to look like Lacey...you know, completely crazy shit stuff...
But Diosvincenccio's explanation, and reveal that those pics at the end are coded, so not a writing mistake, the doppleganger look alike idea is just bat-shit crazy...
I'm going to read something that doesn't make me think so much, and just wait for the next update to this one.
Because I'm not going to overanalyze this one, again. Nope, not going to do it... I mean it this time...