I think the point is that if you load an empty profile (no photos, no videos, no apps, etc) but your phone storage is nearly full, it could throw up a red flag.
That’s why the fake profile would not show that the storage is full. Unless they try to load lots of data onto the fake profile it would not be obvious.
It should work like truecrypt used to where there’s no sign some of the encrypted blob is not actually visible in the fake os.
I think the point is that if you load an empty profile (no photos, no videos, no apps, etc) but your phone storage is nearly full, it could throw up a red flag.
That’s why the fake profile would not show that the storage is full. Unless they try to load lots of data onto the fake profile it would not be obvious.