Consider phones like the pixel 2, Samsung or iPhone X with notches and non rectangular screens. How is the screen resolution calculated? Do they take a rectangular screen with a standard resolution and 'chop off the edges' and use the regular value as the resolution?
Okay I asked ##techsupport on freenode and they answered it. If anyone else is looking for the answer:
The resolution specifies a rectangular screen with the same width and height of the screen. Rounded edges and notches are the rectangular screen with the appropriate bits cut out