The difference is during the first time you meet Melurin. If you submitted to both the previous elves(either through combat or simply going through their foot worship scenes) you will get the line about grovelling in the dirt when confronted. If you submitted to neither and beat them in regular combat she will say you bested her soldiers etc. Any other case you won't get a dialogue at all.In my case, after the dialogue with Clessa and after talking to everybody in the village, I (a) defeated the ranger at the gate in combat, (b) defeated every other lady in the forest until I got to the elven queen; by that time I had no food left, so I simply submitted to her. Still all I got was "I've heard you've been submitting to everybody, like a human should", or something like that. This wasn't supposed to happen? What kind of combat/submission ratio triggers different dialogue? i can try again to see if there's something wrong on my side.
I can't find the line you are referring to in her pre battle dialogue. If you got it after you submitted to her that's normal.
Like I said I tested it yesterday and it works as intended at the moment. So I really can't figure out what's causing your problem. I can only guess you either didn't start a new game(which would just result in not getting the dialogue) or went through with the foot kiss and shoe cleaning scenes with the elves that block your path.