This setting is to tell the website to show the language set by user.
In current version of Orion, I noticed that website always show in English by default.
While the same website I visit by firefox will show Chinese instead.
For example, I can set preferred language in this order. Chinese -> English -> Japanese.
If the Chinese version of the site is available, the site will show in Chinese.
If the Chinese version is not available, it will show English instead.
If the English version is not available, it will show Japanese instead.
This is the screenshot I took from firefox.
You can check how the menu looks like.

Thank you.