On the page, under Usage, it says that the shadow crystal check text in the chapter 3 dark world "foreshadow[s] possible snippets of the future" which isn't true, because the only time you get to check it is after Tenna gets slashed by the Knight and the "television [got] smashed to pieces" already.
I posted this here to see if anyone else saw this discrepancy
It’s because of the scrapped dialogue which has Undyne Frozen in Ice if you look in the glass.
Thanks for bringing this up. I removed that line from the section now.
Yeah but the crystals do seem to be related to The Inverse chapter, in chapter 4 they show the opposite dark world you are in for example, in chapter 5 looking in them is called useless, the scrapped chapter 3 is Undyne frozen in ice, etc. So it might still do so but the location of Chapter 3’s crystal may be why.