This is probably one of the most touching scenes that I've seen in an anime in quite some time and what a pleasant surprise to see someone take a screencap and vector it.
While I really like the work you did with the vector, and the tear work paid off, it's a shame that the background isn't more than what it is. While I do agree that a simplistic background is best so to help the feeling expressed take center stage without interference from a noisy background, I would recommend working with it a bit more in the future to help further elevate the emotion. As of right now, it just seems..sort of bland compared to this incredibly emotional scene.
Overall, it's a rather nicely done wallpaper, but I'm torn. While I really like the vector, I also feel that overall it could be a lot more. Still, very nicely done!