The Knowing of the unreal can be compared to a negative feedback loop. Just as this knowing reveals the causes of compounded phenomena to show that they are evanecent, so the negative feedback loop constantly cancels itself out to produce a steady state, analogous to the ground of knowing.
Whereas the Knowing of the real can be compared to a positive feedback loop. Just as the knowing of the knowing is a bright, steady, robust phenomenon; the positive feedback loop can be seen as an analogy with its successive reinforcement or amplification of a phenomenon.
This is a rather tacky analogy, but it does point out the stark differences between the Real and the Unreal that the deluded mind constantly denies, and the knowing mind can't mistake. Such is the power of either careless atachment or the pure Citta.