Probably due to the white balance of the camera not being properly set up. The Pixel 2 XL should have a very warm display when looking at it head on, like at the beginning of this video. Here's some quotes from Tom's Guide about the warmth of the XL2 display.

"The iPhone 8 Plus has the finest LCD screen you’ll find in a smartphone, and the same can be said of the Galaxy S8’s curved AMOLED panel. Looking at the Pixel 2 XL sandwiched between them, Google’s flagship clearly demonstrates an overall warmer tint, almost like the phone’s Night Light mode has been switched on"

"Thanks to its True Tone display, the iPhone X can adjust its white balance to ambient lighting conditions. But even with True Tone off, our unit struck a perfect medium between the warmth of the Pixel 2 XL and the cool shift of the Note 8 in our office."

https://www.tomsguide.com/us/google-pixel-2-xl-screen-comparison,news-26015.html

https://www.tomsguide.com/us/iphone-x-oled-screen-vs-pixel-2-note-8,review-4807.html

People don't seem to understand that cameras have a hard time balancing the color white and almost always make things look either warmer or cooler than they are in real life.

So judging by own time with my Pixel 2 XL and what Tom's Hardware says, there is no cool cast over the screen at straight on angles like is being shown in this video. The intensity or the blue tint at angles also doesn't look as intense in real life as it does in this video.

While I'm still betting the Pixel 2 XL has worse blue tint than at angles the iPhone X, I don't think this video is a accurate compriason due to the white balance of the camera not being calibrated right.