I frequently unlock a phone that's flat on a desk that's at an arm's length. Now, to unlock, I suspect I'll need to lift and point that device towards my face in order to authenticate. Since I haven't tried the iPhone X yet, I'm not sure how liberal they are with the angle required to capture your face, but it seems unlikely this can be done with the device flat on a desk.

To me, that's unfortunate ... and it's a feature change that having TouchID integrated into the display, as was rumored to be their original intention, would have avoided.