If the new Nexus 7 can have a Retina-like screen, why can't the iPad mini?

Article cited from iMore.com by Smartphonebay.net
If the new Nexus 7 can have a Retina-like screen, why can't the iPad mini?
If Asus can get Google's new Nexus 7 to Retina-like densities while retaining its small, 7-inch form factor, why can't Apple do likewise and launch an iPad mini Retina? That's a question that's been asked again and again since Google introduced the Nexus 7 earlier this week. Last fall, when Apple launched the iPad mini, it was with their standard 1024x768 panel at 163ppi. Going to Retina would require the double LED backlighting, quad-core GPU, and power demands that come with it. That meant either shorter battery life or a thicker, heavier body, both non-starters for Apple back in October of 2012. So how could Asus do it now, and what does that mean for Apple?
Well, first lets compare Apple's to Asus':
  • The iPad mini is 7.87- x 5.3- x 0.28-inches and weighs 0.69 lbs. It currently uses the aforementioned 4:3 1024x768 (786,432 pixel), 163ppi screen, and gets 10-hours of battery life.
  • A theoretical iPad mini Retina would need to stick very close to those same size, weight, and batter life measures, but bump up the display to a 4:3 2048x1536 (3,145,728 pixel), 326ppi monster.
  • The Nexus 7 (2013) is 7.87- x 4.49- x 0.34 and weighs 0.64 lbs. It now uses a 16:10 1920x1200 (2,304,000 pixel), 323ppi screen, and gets 9-hours of battery life.
So how close does the new Nexus 7 get to what an iPad mini Retina would need to be? Close but not close enough. It's a little thicker, and more importantly, it has only 3/4 of the amount of pixels an iPad mini Retina would need, and even then at only 9/10 the battery life. In other words, the Nexus 7 (2013) is thicker, has less pixels, and less battery life than a theoretical iPad mini Retina.
While impressive in its own rights, those still aren't the numbers, and certainly not the formula, Apple wants to hit.
Apple, I'm guessing, wants the same or similar thinness - technically lightness, but they use aluminum instead of plastic for the chassis so it needs to be thin to be light - from an iPad mini Retina as the original iPad mini, with four times as many pixels, and with the same battery life. And the devil most certainly is in those details.
There have been advances in LED backlighting, and in display technology, in systems-on-a-chip, and in operating system battery optimization that might let Apple hit all those measures. But they weren't in place last spring when the original iPad mini launched. Whether or not they are in place by this October, the same time this year that the original iPad mini launched last year, we'll have to wait and see. (That's perhaps the reason for the seemingly conflicting rumors of fall 2013 and spring 2014 releases - best possible and fall back windows.)
Much like the first Nexus 7 showed the small tablet form factor has potential, the second Nexus 7 shows the high density small tablet form factor has potential. It wasn't where Apple needed it to be before, but it's coming. Of that, have no doubt.
Comment from Smartphonebay.net:
High Resolution display is absolutely one of the advantage for Nexus 7 in the competition with Apple iPad. The reason why we think Apple do not install high resolution display to iPad may due to the limitation of battery life. One thing for sure is high resolution display panel will consume more energy from the battery. When compared to new iPad mini with Nexus 7, iPad Mini advantage maybe the battery life that is mostly concerned by user these days.

It is so exciting to see which brand will go to the lead of tablet market. Battery life is being concerned more or higher specification is at higher consideration? We are excited to see the choice of customers in the coming competition!!