Uploadvr demystified this stuff a couple years ago:
http://uploadvr.com/magic-leap-how-it-works/
Magic leap is a pair of glasses you wear on your face that displays AR imagery through a clear glass lens. There's a cable leading from these glasses to your pocket where you have a tablet-size device doing all the heavy lifting, most likely using mobile SoC's. Pretty sure you can't run a desktop CPU and GPU on a pocketable device.
You don't get 1080gtx performance or anything remotely close to that with a setup like this. Its mobile-level graphics. Oculus's recent showing of its mobile SoC-based Santa Cruz prototype shows fairly poor graphics compared to PC-based VR like the Rift or Vive. I imagine the Magic Leap has less pixels to push considering it isn't doing any backgrounds, but still, those very impressive marketing shots of high resolution dragons flying around and interacting with you might not really be possible without a lot of compromises on graphic quality, fov, framerate, etc. Worse, no one wants to talk about transparency, especially in well-lit rooms. The few hands-on Hololens reports we've gotten make this out to be a big issue, as well as fov, and fundamentally the Magic Leap and what hololens is using could be the same or very similar technologies.
My gut feeling is that no one has yet to handle the transparency issue (and this is why MS can show off the hololens with confidence) and because of that it makes sense for Magic Leap to keep its product secretive. The tech press was not too kind to Hololens prototypes due to transparecy issues and Magic Leap doesn't need that kind of negative press as it continues to fund-raise and develop its product.