Well, I’m not sure of the exact reason why Leiko would show up during that time of what is being described in those posts because I don’t think I have encountered her while someone else was in the middle of their animations (with the exception of Elina’s spectral hands still being on screen).
Update: Okay, after looking at the photo featured in the comment below me by the original poster following the comment you made to them, I can confirm that that was not Leiko and I have no clue of who that was.