The "Ian knot" that people are discussing is neither square nor granny knot in and of itself, but how you make it: The technique of having a loose loop in each hand and "pulling both through each other", which is much faster than tbe "ordinary" ways of making each that he presents on each separate knot's page. Topologically it results in the exact same end result: Do it the right way around and you get a square knot; the wrong way, a granny knot.
A bit weird of the tomtenisse to link to that exact page of the site; granny knot / kärringknut is the absolute worst result you could end up with. The whole site is pretty much about how to avoid ending up with one. (OK, slight exaggeration there.)