[Demeisen offers no rebuttal to Sebastian’s skepticism; he has his own doubts that the man would in fact be able to tell the difference, but there’s no reason to belabour the point when the entire issue is that it would be impossible to tell either way. Instead, he considers the question.]

Essentially, it’s as simple as reading it.

[He has no intention of attempting to explain the technology involved to this person, both because of his unfamiliarity with even modestly advanced tech, and because he simply doesn’t need to know. The Culture has long benefited from a bit of an aura of mystery when it comes to what the civilization is truly capable of.]

A very rough analogy would be to imagine a person’s mind-state as a journal, copied in its entirety at a precise moment in time. Every letter, every mark, every errant scribble or smudge represents the person’s thoughts, feelings, experiences and so on. Whether the mind is bio-chemical, mechanical, electronic, whatever—

[Demeisen slices his free hand through the air.]

Doesn’t matter. Complexity of the mind would affect the difficulty of accessing and parsing the information, but not the broad mechanics. So: you could read the journal easily, but it wouldn’t be much harder to edit it, make additions, or rip pages out. And of course—if you wanted—you could also reproduce it, even if the original still existed.