This way you have a clear face, a hidden but revealable one, to state that's why I use this tool, and no can say you have if also for something else. A part of a real deniability is proving why you have some code in your system.
> In Shufflecake, each hidden volume is encrypted with a different secret key, scrambled across the empty space of an underlying existing storage medium, and indistinguishable from random noise when not decrypted. Even if the presence of the Shufflecake software itself cannot be hidden - and hence the presence of secret volumes is suspected - the number of volumes is also hidden. This allows a user to create a hierarchy of plausible deniability, where "most hidden" secret volumes are buried under "less hidden" decoy volumes, whose passwords can be surrendered under pressure.
And wait when we'll release a Shufflecake-powered, fully hidden multi-OS distro ;)