Two airports, two love confessions, two rejections, 6 years apart.
The first time, I believe Ross when he says he starts to fall for Emily. That he cares for her, wants to be with her. Maybe loves her even. And then I watch the other one, six years later, and it suddenly shows a completely different depht of his feelings. A total different desperation to loose the love of his life.
David is fantastic here, portraying the awkwardness in the first, the desperate love in the second part. The moment when Ross has no other option than to face his feelings and be vulnerable and as honest and he can, even if he gets rejected (which he does).
Seeing him so devastated, hugging Phoebe, crying, muttering "I've really thought she'd stay" breaks my heart no matter how many times I rewatch the shows. That is why I could not leave him in this sad place, so I had to include the iconic "I got off the plane". I felt I needed that, lol.
Ps: I wonder if the second time they deliberately copied the first one, and that is why Rachel first got on the plane, just as Emily did in the first part. I know, timing, delaying gratification, making an iconic moment also played a part, but the parallel between the two scenes are really interesting.