I believe in the context of that quote, I meant it as “if you aren’t presuming that panels right next to each other are related as moments in time, then there’s no reason you should be limited to looking only at immediately juxtaposed panels at all.” The “relational aspects” have to do with looking at the connections that are made between panels’ content — immediately juxtaposed or otherwise.

Once I stopped looking at immediate juxtapositions, it lead me to the “Webdiagram” approach of grouping transitions in Early Writings…, and that gave way shortly to abandoning transitions altogether (in the “Visual Syntactic Structures” chapters). Incidentally, much of the alterations of the theory came (and still come) from trying to apply it to actual sequences.