http://appleinsider.com/articles/12/10/23/ipad-mini-ignores-unintended-touches-near-bezel
"For iPad mini, we reduced the width of the bezels on two sides of the display. So although the screen is smaller, it’s even more prominent. Rethinking the screen meant we also had to rethink the software behind it. iPad mini intelligently recognizes whether your thumb is simply resting on the display or whether you’re intentionally interacting with it. It’s the kind of detail you’ll notice — by not noticing it."
"For iPad mini, we reduced the width of the bezels on two sides of the display. So although the screen is smaller, it’s even more prominent. Rethinking the screen meant we also had to rethink the software behind it. iPad mini intelligently recognizes whether your thumb is simply resting on the display or whether you’re intentionally interacting with it. It’s the kind of detail you’ll notice — by not noticing it."