They're probably using 1080P as the definition of HD.
The last time I looked at buying a movie in iTunes, the max resolution they sold was 720P.
The last time I looked at buying a movie in iTunes, the max resolution they sold was 720P.
iPad mini has 768 pixels, but the display is 4:3. It will not display 720 lines without distorting the video. Or cropping. To play 16:9, it will be displayed as 1024x576 with black bars at top and bottom. 576 happens to be SD PAL.