Not the original commenter, but I think I know what they were getting at. Basically a given command may do something "different" with regard to the bare text, d

Not the original commenter, but I think I know what they were getting at. Basically a given command may do something "different" with regard to the bare text, depending on the start position in an S-exp. For example, in these two (where | is point) (foo bar |baz) vs. (foo bar |baz) moving "up", point will end up on the same line in the first and two lines up in the second. This, of course, is the point of structured editing, but it takes a bit of getting used to I think, and at first commands can seem sort of "unpredictable" or, as said "context sensitive" in a way that's different from more basic movement. (Though comparable to something like M-a for prose, of course.)