The E06 pocket dimension.
That falls into scifi-fantasy genre. There's nothing much to it.
Yes, I do agree it was very odd for it to suddenly turn that way. For me it was hilarious because that's the typical route newbie creative writers take. Creating an ending is as hard as writing the first chapter. 😝😁
However, after watching the entire episode, I realised it was an artistic way of telling a psychological, sociological, and morality type plot for only 6 episodes.
For example, the 1 year time jump, there shouldn't be any questions as to what happened during that 1 year. Why? We've seen it in sample cases from E01 to E05. All those cases were social experiments, a minor taste of what will happen.
And the detective represent those who would use it for "good".
Going back to scifi-fantasy. If you really want an explanation about the pocket dimension, you're free to make your own. That's part of this story's art.
As the 2FL explained, she simply is a mouthpiece to humanity's deepest secret desire to see sexual relations. Or, to put it another way, she is like a g-d that was created and made powerful by humanity's desire. And her sole purpose was to bring S-Day, and she did.
That's it. Don't think about the scifi-fantasy part, really. Focus on the main plot: How humans, like YOU, will react if you can suddenly see S-Lines. That's the whole message.
