All the observer is sensitive to is the causal graph, or the multiway causal graph....
If the “brain” of the observer corresponds to a certain sequence of events, how do other event affect these?
The “brain of the observer” is a certain timelike separated sequence of events....
How does the observer make a model of reality?
Case 1: wait for things to affect the observer
Case 2: try to extrapolate even outside the past light cone
Observer at a given step makes a summary [?]
Observer makes a model of the universe ; e.g. a spacelike slice