[devit]

I fail to see how they can possibly do this in a way that isn't trivially worked around by just embedding the same code as the full browser.

I guess their best bets are detecting non-fullscreen screen sizes on mobile, requiring Widevine or requiring Chrome and adding some proprietary authentication code, but all these are problematic and can be worked around.

Also of course both Firefox and Chrome support automation via WebDriver and WebExtensions so not quite sure what they plan to do with "The browser must not provide automation features".