https://techcrunch.com/2017/10/26/google-responds-to-pixel-2-xl-display-complaints-promises-fix-for-clicking-noise-on-the-pixel-2/

Shortly after Google’s new Pixel 2 and Pixel 2 XL began shipping, some users noted that the devices seemed to have some… quirks.

Onscreen colors on the XL seemed faded, some users reported. When switching screens, evidence of previously displayed images sometimes seemed to linger (as if they were burned into the screen). Others reported that the screen seemed to turn an odd shade of blue depending on your viewing angle. Meanwhile, Pixel 2 users reported hearing high-pitched “clicking” sounds when on a call.