you are right, the game doesn't look so clear like the desktopthe whole image is pixel perfect screen shot, but the image inside desmume has lost of compression artifacts, it was taken from the intro videoProof please? Looks legit to me >.>that image is faked.
Well, in emulation, many emulators skip loading tiny things to speed up performance, Also there is a max resolution of 256x192 per screen.
Though it COULD have been recorded using a DS capture device and then edited onto the emulator screen.