Lab tests on the recently released iPhone X place the new flagship product of Apple in the highest levels of quality with respect to display and the. camera, but that's only in the first category. Of course, what good is it to have great pictures if your screen can not display them correctly?
Apple does not tend to do its own displays; but while LG, Sharp, and in the case of the iPhone X Samsung rightly deserve credit for doing so, Apple does not just tear them off the shelf. A ton of money and time is spent on personalizing and tweaking, and the phones are individually calibrated before being shipped to account for variations in the manufacturing process.
The DisplayMate test battery aims to test the absolute accuracy of colors, brightness and other objective measures of a display. And by these measures, the latest iPhone beats even the latest OLED screens from Samsung, their parent company, so to speak.
OLEDs naturally excel in a number of categories, from contrast to color accuracy, and Apple's software emphasizes these strengths. Its color accuracy in particular is the best that DisplayMate has tested. And conveniently, it switches to the right color profile or color range depending on the content, which means you will not see the images intended to be displayed in sRGB for the purpose of Adobe or DCI -P3.

The iPhone X nails just about the entire extended range without any weakness in any field whatsoever.
If that does not tell you anything, do not worry – the whole problem is that you do not need to be aware of it and you can just make sure that the pictures, the movies, the games, etc. seen exactly as they should be. All the same, you might want to spend some time in the viewing options, because the auto white balance can throw sensitive viewers at this stuff (me, for example).
A change to display technology that can be considered lateral is the shift to diamond subpixels. As you know, each pixel of a digital display is usually composed of several subpixels: different numbers and shapes of red, blue and green that illuminate to various degrees to form together the colors that we perceive.
For LCD screens, this often takes the form of an RGB grid, usually with a square composed of a red, a green, a blue, then maybe another green subpixel, or something like that. This worked well but led to some alias patterns, or rasterization. Different subpixel layouts produce different patterns of aliasing.
The layout of the iPhone 10 subpixels is different from that of all previous iPhones in that the pixels are diamond-shaped and arranged in a diagonally symmetrical grid rather than rectangular and on a grid rectangular:

This is a super-close-up of the OLED sub-pixels.
Now, since the advent of more than 300 PPI screens, aliasing is posing far fewer problems than in the past. But some types of aliases are preferable to others, and it happens that the type presented by the iPhone X (and others in the diamond arrangement or Pentile) It's not ideal for vertical and horizontal lines.
This comparison photo taken for the phone review by iMore illustrates this:

Definitely see this in real size if you want to see the difference.
On diagonals and rounded edges, the diamond pattern allows a more natural curve without stairs. But in horizontal and vertical straight lines, you end up with a sawtooth pattern.
In other words, if you look at the phone through a microscope. While the jagged sawtooth was a problem on the original Galaxy S, we have come a long way and the pixel pitch is much smaller now, making the pattern, while it's still there, much less noticeable . (I also say this having not looked at the thing in real life, and no one has complained so far as I know.)
The camera rivals the best
DxOMark has tested all the flagship ships this year with a new set of mobile-based tests, and while these semi-synthetic measures are still taken with a grain of salt, these people know what they are doing. they do and are of course unregenerated pixel-peepers.
The iPhone X surpasses the previous high score in the photos, beating very closely the Galaxy Note 8 and Huawei Mate 10 Pro; it's also better than the iPhone 8 Plus, which itself was briefly a high-water mark. So, it's excellent, as our reviewer has found.
As you can expect in a phone with a fantastic screen, the color and contrast are particularly well captured. However, like other Apple devices, its shutter lag was often longer than the competition, especially the Pixel 2, which set a new bar for the speed and accuracy of autofocus.
He lost points in an extremely dim light, where he was also beaten by the Pixel 2, and his flash portraits seem to be regularly underexposed. That's where he also lost points in the video: the noise and under-exposure marked his 1080p / 30 video.
It seems however that under good conditions, the iPhone X is as unassailable as its predecessors and competition.