[Miademora]

I doubt its about size. They can ship the iphone with retina but not the ipad mini.

[supercoder]

960x1136 vs 2048x1536 is a significant jump. It's 2,055,168 more pixels, which itself is almost 2x as many as the iPhone.

One big issue is the higher the density in pixels the larger and brighter the backlight needs to be and in turn means a larger battery, more weight and thickness.