Function for temporarily storing and archiving unnecessary data files. Same as a trash can.
In Passionlip’s case, that icon is set for some reason at the center of her chest.
To put it briefly, it’s a pocket of imaginary numbers where you can accumulate all the trash you want.
If it’s dust data crushed by Passionlip, they can be infinitely stored no matter the capacity. It seems that even those exceeding Lip’s own memory can be dumped into this valley.
Although it looks like a convenient function at first glance, since the dust data won’t return to their original form, it’s a completely meaningless function.
Passionlip is thought to have gained this particular structure because she’s a self-destructive/self-harming type of girl that keeps her feelings inside.
In 『CCC』, once something fell in this valley of death it wouldn’t crawl up again, but in 『FGO』she became able to scoop up the contracted Master.