With a typical Kabbalistic flexibility they can also stand for the six days of Creation. The illusion of Tiphereth is Identification. It is extremely common for people to identify what they are with the totality of their beliefs and behaviours, and they will defend the sanctity of these beliefs and behaviours, often to the death - a person might have behaviours which make their life a misery and still cling to them with a grip like a python. When behaviour and beliefs are unconscious and incorporated into a sense of identity it becomes impossible to make sense of other people. There are many behaviours which may seem innocuous to the person concerned but which are irritating or offensive to others, and when the injured party reacts appropriately it is impossible for me to make sense of this reaction if my behaviour is unconscious and tightly bound to my sense of identity.
Projections change the world into one's unknown face.
In summary, the illusion of Tiphereth is a false identification with a set of beliefs or behaviours. It can also be an identification with a social mask or Persona, something discussed in the section on Netzach. Out of this comes a sense of emptiness, of hollowness. The intellect attempts to solve the koan of koans but has no anchor to hold on to. This sense of emptiness or hollowness is the Qlippoth or shell of Tiphereth, Tiphereth as the Empty Room with Nothing In It.