Screen Size doesn't change with customizing Firefox toolbars
The Screen Size in Tor Browser is forced to 1000x600px at my screen size. However, when changing the layout of the Toolbars via "Customize -> Density", the window stays the same. Even after hitting "New Identity", the window size stays the same, so the toolbars "eat" more (or less) of the inner screen size. You can run Panopticlick with the three different density settings, and only on "Narrow" you will get the 1000x600 (or I assume the other right screen size, if you don't have 1000x600).
I consider this kind of a privacy leak, because some people may change the toolbar layout, and they may think "Am using TB so everything's gonna be alright". On Panopticlick the screen size has a good impact.
Hope i described the "bug" or whatever good enough.