Don't forget the ratio.

It's a 18:9 ratio in 6", in another word it's the same panel as a 5.4-5.5" screen in 16:9. The screen is bigger due to less bezels. In measurements the device is quite narrower and slightly shorter than the Moto Z2 Play.

Thinking this way, it's a 5.4" of the traditional 16:9 ratio.

P.S: Being quite smaller than the Xperia XA2 Plus, which quite some users are happily using SFOS upon.