Quote:

What does this mean?



This means that the phrase "get 'er done" is a parody of the phrase "Getting Things Done" , commonly abbreviated as GTD, the title of a popular motivational book by a guy named David Allen.

GTD rests on the principle that a person needs to move tasks out of the mind by recording them somewhere. That way, the mind is freed from the job of remembering everything that needs to be done, and can concentrate on actually performing those tasks.

That's what "get 'er done" is.