Why is the pixel of Yu 2 zoom version not as good as air2?

The size and optical zoom of the air dimmer are stronger. The 4800 Wan Chao resolution mode of Yu 2 zoom version is to automatically take 9 photos and merge them into a 1 high-definition image, with a height of 48 million pixels, while Yu Ari2 is directly shot by the camera, with a true 48 million pixels, and the size of the photosensitive device is larger than that of the zoom version. Air2 is a tablet computer released by Apple at its headquarters in Cupertino, USA on 201410/7. IPadAir2 is made of aluminum Unibody and has three colors: silver, gold and dark gray.