The Pixel 2 XL, as Google called it, had a circular polarizer to make sure that the screen was visible from every direction on every pair of polarized sunglasses. They made a pretty big deal out of their 2017 event, but in 2018 there was no mention of whether or not this feature would return to Pixel 3.
There was speculation that the circular polarizer was meant to blame it for the "Blue Shift" problem of the Pixel 2 XL – a condition that made the screen blue at steep angles. With all the trouble their 2017 flagship had, some thought Google would abandon this feature in the new Pixel 3 series, but they definitely do not have it:
Polarizers are optical filters that allow only light from certain angles. All smartphone displays have a polarizer, but most are linear, ie they block light when viewed in portrait or landscape mode through a second polarizer (read: polarized glasses). The circular polarizer of the pixel attempts to solve this problem.
We could not test the smaller pixel 3 to see if it has the same circular polarizer, but we will update this article as soon as we know one way or the other.
From our previous tests, the blue shift problem on the Pixel 3 XL seems to have improved. However, you still see a bluish tint at steep angles – only the angle must be steeper than the Pixel 2 XL. Maybe the circular polarizer was not the problem, or maybe Google improved it.