I see. While making this I found that if you hide the Finder sidebar and toolbar (both are options in the menu), then your scenario plays out. In a way it’s nicer than the video on my github.
It's also missing the open folder indicator that the Classic Finder had, where folders that had their window open somewhere had a different icon (filled with a stipple pattern). This is a bigger problem than it sounds like, particularly with OS X having multiple desktops and making it easier to lose windows.