For viewers who want more than just a YouTube video: fullmag.com
From Apple's website about the iPhone 6 Plus:
iPhone 6 Plus isn’t simply bigger — it’s better in every way. Larger, yet dramatically thinner. More powerful, but remarkably power efficient. With a smooth metal surface that seamlessly meets the new Retina HD display. It’s one continuous form where hardware and software function in perfect unison, creating a new generation of iPhone Plus that’s better by any measure.
Designing a larger iPhone Plus without making it feel bigger was no small task. It required challenging the idea of “big.” It called for narrowing when the natural inclination was to expand. It meant condensing powerful technologies and making chips smaller and batteries thinner, all while making them more capable. And it meant engineering our thinnest, most advanced Multi‑Touch display. All of which yields a dramatically thin design.