Imbicatus: So I am assuming that in image one that you are using a reach weapon? I'm guessing it is not a whip (like what is being discussed here) because you aren't attacking at maximum reach there.
So that would make diagram 2 incorrect as well if you are using a whip. So I'm guessing still a polearm then? You are correct in both if you are using a polearm. However, a simple 5' step away from the enemy after making a full attack would accomplish the same task in each scenario and doesn't require spending a feat. I suppose the only exception is the situations where you are unable to take a 5' step.
I think that basically my point is that you shouldn't take Lunge if your intention is to be able to more effectively make AoOs at a greater range as it does not accomplish that.
LessPopMoreFizz: Mythic Lunge is worded differently and does not use the "during your turn" clause. This is likely because Mythic Feats are intentionally more powerful than non-Mythic Feats. But again, RAW, Lunge does not increase your AoO range.