This understanding itself is a consciousness, whereas primordial wisdom is not.

Lopon Tenzin Namdak, in oral commentary, further enriches the point:

New understanding arises on the basis of scripture and so on, but self-arisen primordial wisdom does not newly arise. This [new] understanding itself is a consciousness, whereas primordial wisdom is not. It [new understanding] is like a shepherd, keeping track of sheep and bringing them […]