The guy even hints at the misunderstanding in his code with the comment 'Makes it easier to understand "functions as an object"'. So what, most other languages have this now, but you don't see them taking one of the fundamental building blocking of programs and code encapsulation, simple function declaration, and bunging it in the middle of another method.
It's much clearer using the style for closures only so you're explicitly making it clear 'hey look, I'm making a closure people!!'.
It's a style that's practically begging for you to write heavily coupled code and is anti-code reuse. It's a terrible habit, it was all started by Crockford's the good parts, a style he just happened to be using at the time as far as I can tell, and even he doesn't even do it any more.
It also makes your code harder to read as you can't just move the function declarations wherever you want, just in case.
IMO you should never assign a function to a variable unless you are going to use it as a closure or actually use it like a variable and potentially over-ride it later in your code.
To me it's a massive code smell when I see simple functions assigned to variables.