Mozilla has changed the Private browsing page design and information in it (slightly) for Firefox browser on Nightly, this will soon appear on beta, developer and release channels of browser. Firefox’s PB mode page is not the usual page you’ll see in other browsers like Chrome, Internet Explorer or Opera, because Firefox has recently added tracking protection to it, that makes the incognito mode of Mozilla browser, quite special, powerful and unique.
With tracking protection based on initial blacklists from disconnect turned on, sites load much faster than before, and your privacy is enhanced as no browsing history is saved or no third-party trackers track you. You should note that tracking protection is enabled by default for private browsing session, but not for normal browsing mode.
To see the change for the Firefox’s private browsing page in action, open Nightly (if you’re using) and need click on ‘New Private Window’ in the menu.