These are the statues that block the end area of each layer.
They are the true form of the girls who have been transformed into Sentinels, and thus they are each part of the Labyrinth core.
In the game they are called “relief.” The statues basically have the girls entrapped inside.
They are supposed to be “the border of the world” impervious to physical attacks. Even BB can’t enter the territory held inside them.
BB assumed that even if the protagonist and company made it through Sakura Labyrinth, if they were blocked by these impenetrable statues, they wouldn’t be able to do anything.
However, using the secret technique developed by Kiara, the protagonist was able to jump over the border into the statue interior.
The invincible Sentinel System’s last line of defense fell.
By the way, the massive avatars of the statues that are half buried in the wall are the result of being connected to BB’s expanded memory. It goes to show how much modification was needed to create the Sakura Labyrinth.
Once you get inside the statue, defeat the Sentinel, clean their heart of contamination, and free them from BB’s control (by severing their connection to BB), they will return to their original size.
Their name in the early designs was “Chocolate Veil.”
The inside of the statue is somewhat different from the inner-heart world relief. The inner-heart world should be thought of as the deeply rooted “shape of one’s soul.”