The Galaxy Z Flip is a fascinating phone. The engineering is unlike other folding phones to date. Actually, it borrows ideas from both the Galaxy Fold and Motorola's razr. It doesn't fold 100% "flat", meaning when it's closed, there is a slight gap between the two halves at the hinge end. But it's a much thinner gap than what was on the Galaxy Fold. It's small enough that, at quick glance, you might not even notice it. And yet, unlike the razr, there doesn't seem to be any special mechanism that gives way to let the screen bend with a gentler curve radius. The screen really does just bend in half with a shockingly tiny radius, almost like folding a sheet of paper. I worry about the long-term durability of a screen that bends so sharply, but Samsung says I shouldn't, that its unique engineering - particularly the ultra-thin flexible glass layer - will keep it working reliably. And that bending glass layer is part of the real magic of this phone. It should provide dramatically better durability, and it also changes the feel of the screen.