A new support document discussing the Super Retina OLED display in the iPhone X addresses user viewing angles, as well as the possibility of image persistence when a display shows a faint remnant of an image that hadn't moved in a long period of time.
"If you look at an OLED display off-angle, you might notice slight shifts in color and hue," Apple declares in the support page. "This is a characteristic of OLED and is normal behavior."
This manifestation should only occur when a device is being used by two people simultaneously. The "shifts in color and hue" are very slight at narrow angles, and worsen slightly the farther away from a straight-on viewing angle the user gets.
"With extended long-term use, OLED displays can also show slight visual changes," writes Apple. "This is also expected behavior and can include 'image persistence' or 'burn-in,' where the display shows a faint remnant of an image even after a new image appears on the screen."
Apple advises users to avoid continuously displaying the same high-contrast image for prolonged periods of time. The company also notes that it has engineered the display to reduce the effects of OLED "burn-in."
The OLED burn-in "issue" isn't new, and isn't permanent with well-engineered panels. Evidence collected over the last few years demonstrates that retained images are wiped over a brief period of normal time of normal use displaying non-static elements, with the user periodically turning off the device when not in use.
The Google Pixel 2 XL is taking some flak about image retention on its OLED screen. However, the screen is based on LG's pOLED technology, and the smaller Pixel 2 that is not having any problems is based on Samsung's AMOLED process. The iPhone X uses Samsung-sourced screens.