Woo, inconsistent crazy theory time. Oh yeah, spoiler alert too.
Personally, I think the area represents death, or is a memorial to someone's death.
-The darkness in the tunnel, the flowers, and the color white are all evocative of death and mourning. Perhaps Mado created this area so that she could go there and feel closer to whoever she had lost (possibly Poniko, Monoe, Monoko, Masada, or possibly all of them), which I guess makes it like a gravesite.
-The only problem with this is that she can already visit her friends in her dreams if she wishes, so why would she make a grave for them? Maybe this area is there to remind her that they are gone in real life, though they continue to live in her dreams.
-The person(s) in question who the memorial is made for may be someone she doesn't remember- perhaps her parents died when she was a young child, since there are no representations of them in her dreams. Since she doesn't remember their appearances, she has no analogue for them in the dream world. Because of this, she created this area as a grave for them. This is all speculation, though.
Or:
-Alternatively, perhaps the area is Mado's concept of death, since the flowers teleport you to a tomb-like, seemingly underground area. With ghosts and.... uh, chromosome-amoeba things.
-If we interpret the flower-filled area as a tomb, the act of going there corresponds to connecting with the afterlife by visiting the grave of a loved one. The flower-filled area might also be an analogue for "the light at the end of the tunnel" cliche. When Madotsuki enters, the light in the doorway is eerily red, not at all warm or welcoming, possibly symbolizing blood (can't be a YN theory without some reference to violence, right?) and by extension the end of her life. Once she interacts with the flowers, there is a flash of bright light and the light in the doorway changes to a somber blue-grey, possibly showing that Mado has "crossed over" to the other side.
-The underground area in question may represent the interior of a grave or a tomb, the ghost might be Mado herself- or Mado's interpretation of herself after death.
-The reason for this area? Mado might have been contemplating suicide before the events of Yume Nikki and possibly created the area to ready herself for it. This all hinges on whether or not you believe that Mado dies, though.
-Perhaps the amoeba represent bacteria/decomposers that will destroy her body after she is laid to rest, leaving only her soul (the ghost).
-Finally, and most obviously, the ghost gives you the triangle kerchief effect, which turns Mado into a ghost too, perhaps foreshadowing the ending of the game.
This is all wild speculation, so don't take it srs. I just kinda typed shit out.
Last edited 10/07/23(Fri)13:30.