In the promo video, they say "it's small enough to fit in one hand" at time 0:49, but later at 2:29 Ives says, "you can still pick it up and easily use it with one hand."

https://www.apple.com/ipad-mini/overview/#video-ipad-mini-fe...

Clearly he meant that you can pick it up with one hand, and use it with the other. Nobody thinks you can physically operate the ipad mini with a single hand.

You can probably scroll or flip pages with your thumb, so it might be comfortable to read long content with one hand (like a kindle).