The Asus ZenFone AR comes with a large 5.7-inch 2K Super AMOLED display. The reason why this display is super important is that it need to enhance the AR and VR capabilities of this smartphone. Augmented reality really work best with larger screen, for the reason that the screen itself is the window to the projected real physical world. Because the virtual objects are presented and projected over the physical world, some objects can appear very small because they need to be a part of the augmented reality space and not like regular apps where objects in apps and games are designed to take a lot of the space. So larger screen improved the visibility as well as the overall AR experience.
The same goes to virtual reality. A larger screen is recommended in order to cover the maximum supported field of view with the Daydream View VR headset and the higher resolution and higher pixel density is essential for delivering smooth and more believable experience. Watching VR on low resolution screen really hurts the overall experience because the magnification of the screen and the fact that each eye gets half of the resolution, allows you to see the screen pixels. I remember playing Cardboard games with my iPhone 5S and it was a terrible experience with terrible pixelation and limited field of view coverage.
So this is why the large high resolution screen is great to support those two technologies. It's also good for all other task, including playing regular games, browsing the web, watching movies, etc.
This is also a Super AMOLED display, so you get to see very vivid visuals, which is also great for consuming content in VR and AR, and it's actually essential for VR due to its fast screen response rate. The screen also come with Gorilla Glass 4 cover glass protection. The phone has a 79% screen-to-ratio body and the screen has 515 ppi pixel density.
So overall, the superb display of the ZenFone AR really helps makes the whole experience of using the device much better.