Also which is the comment they're talking about? I can't seem to find an anonymous one talking about this on the original post https://terrytao.wordpress.com/2011/08/25/the-collatz-conjec...
https://www.jasondavies.com/collatz-graph/
One of the first results if you Google "collatz online". That's also probably why it's confusing - because it wasn't made for the article.
It doesn't contain number 9, so I somehow miss what it was supposed to demonstrate.
Take 16 and 5. While 16 is shown first and 5 after, the meaning is actually that you can get from 5 to 16 by applying the odd rule (3*x+1) and from 10 to 5 by applying the even rule (x/2).
- usefulness of animation
- the non obviousness of the numbers that are displayed, v.s. all other remaining in the observed range.
At least, non animated version of end frame allows better comprehension of what is shown.