Not sure what to think about these articles "Develop X in Y lines of JavaScript". If the goal is to learn then clarity rather than number of lines should be the goal. And if the number of lines is the goal then it's a bit pointless since any program can potentially fit into one line of minified JavaScript.
I'm not sure where exactly the author got the number 25 from either, even without counting comments or white space this is somewhat more. Of course, as you say, it can be any number of lines you desire it to be.