I can think of a couple of instances when that kind of annotation would be used. It can mean preventing an enemy rook from moving onto the file, it might be said when you're preventing the enemy king from crossing to the queenside, or it can mean preventing any enemy pieces from occupying the e file (even if only temporarily).
Of course maybe a legal series of moves could challenge the e file, but the annotator doesn't mention it because it would require a lot of concessions. Lets say it would take 5 passive moves of prep to finally, on the 6th move, challenge the e file... well with 6 moves white might win all the queenside pawns, so this would never realistically happen.
If the annotator assumes a strong audience, then sometimes comments can be confusing. Like ____ controls e5 even though there are legal series of moves that could challenge e5 or take it away from the opponent. The annotator assumes his audience understands how each of those options involves concessions so that those moves would never actually happen.
Firstly, let me thank all those who answered my question on the difficult subject of compensation. Now, if I may, I'd like to pick your brains about the subject of 'control' in chess. What does it mean to be in control of a square, rank, file or diagonal? I ask because I am trying to make some inroads into assessing chess positions, and, unless I can get this problem sorted out, it becomes very hard for me to decide who stands better in a given position. As an example, I was playing through a game a few months ago and white moved his king rook to e1, where the file was fully open. The annotator's note said '...and white controls the e-file.' But, when I looked, I saw that the only other square that the rook could occupy, without being captured by lesser valued black pieces, was e2. So, if the rook could ONLY move from e1 to e2 without being captured, then how on earth can it be said to be 'controlling' the e-file? Thanks guys.