I want to make sure that I understood what was happening in the scene where the turbo lift door opens and they see an alternate reality... Those were the Enderprizians from "All the World's a Stage", right?
Since we never got a mirror universe episode in Voyager (not counting "Living Witness"), I enjoyed Mulgrew and Beltran getting to give us a quick glimpse of what it would have been like.
I loved the callback from Chakotay regarding the events from the VOY episode "Shattered".
Those were the Enderprizians from "All the World's a Stage", right?
They certainly appeared to be - how that's possible is an exercise left to the viewer, which is part of the fun of alternate universe stories.
That said, this is the first episode of the season that fell a little flat for me. I know part of the show's mission is to give a bit of a "grand tour" of Star Trek, but this is the first one that seemed a little contrived to me.
Part of it is probably that I prefer the Mirror Universe to be more scary than silly, and the episode understandably leaned into the silly.