On the surface, it could be viewed as old-school, selfless, and romantic. Commencing the journey together, they have a shared dream. Along the way, despite his sacrifices and best efforts to support their endeavor, he realizes they won't be able to reach the moon together. Selflessly, he still wants her to achieve the experience - even without him. With the help of another, he can support this to happen. She's sad to part; he's happy in knowing this is something he could provide her.
Viewed through a different lens, which is completely left-field from the above, the climb to the top is incredibly difficult to achieve, as represented through the length of the ladder to the moon. Even with determination and sacrifice, the availability of resources makes the difference. The pilot was able to readily get to the moon as he had the resources available to him, okay, and likely some sacrifice and determination of his own, too. Utilizing his capital, the pilot provided her with the opportunity towards social mobility.
And yet another view, is how seemingly unempowered the woman is throughout the illustrated narrative; aside from showing up and demonstrating a small amount of effort at the start. To make it a little more cynical (why not, eh?), she could symbolize how the dominant view of physical beauty, versus effort, is rewarded.