Unless the option "show full address" is checked, the address bar will only display a section of the URL until focused. For instance when watching a YouTube video all you see is "www.youtube.com/watch". Even the "https://" is elided. That's neat!
I use a lot of inline full-screen to keep my panel-clock in view while watching stuff. I'd also like to not have to see a URL spanning the greater part of my toolbar when I do that.