Not a correct representation of how iPhone X handles websites.
I'm sorry, but this isn't at all accurate. When you view a website on iPhone X (that hasn't been especially optimised for iPhone X), it automatically adds margin down the left and right so that the notch and rounded corners do NOT obscure any content.
See these screenshots:
iPhone X Tester: http://spdr.me/gdl8C
Official iPhone Simulator: http://spdr.me/XSyGgP