What is the observer that can’t be seen as content? That aspect of consciousness which is just receiving and processing does not have a spacial dimension or a time reference. It doesn’t have an identity, particularly. You could call it tathagatagarbha, jnana, prajna or wisdom. Even calling it an aspect is going too far. This and other questions from sangha are addressed in depth in this talk.
https://www.youtube.com/watch?v=ln_M-9lv_-Q