The original Lytro camera was a little rectangular object that took square photos. It looked neat, but the design wasn't great for taking photos.
The Illum gives photographers more flexibility than the former version. The newer model is much larger than the older model, and looks more like a standard DSLR.
There's also a four-inch touchscreen that allows you to adjust the "center of focus" for the final version of your photo.
The price of the Lytro is pretty high. It will ultimately cost $1,599. If you preorder before July, then it's $1,499. The best rated DSLR cameras sell for $700-$1,100.
While it's easy to scoff at the Lytro's high price, a chart from GfK Group (via Twitter) shows that in 2013, premium camera sales began to catch up to point-and-shot camera sales. For the previous four years, point-and-shoot camera sales had far outpaced premium camera sales.
The problem for Lytro is that its main selling point, photos that can refocus, has been copied by Samsung and HTC. Therefore, it's hard to imagine shelling out for a Lytro unless the camera is significantly better than the best DSLR.
Here are some GIFs that show how the Lytro Illum can re-focus images:
Lytro
Lytro
Lytro
Lytro