Does this mean you can use this to print/hand-write a book, fold it, and hand-sew it? This folding process produces a sextodecimo signature, with all the pages facing the right way, so it seems to be a smart way to do it. However, this example shows how printer's do it, with the page numbers 'jumping' from edge to edge. The mini-book example here is more linear, in it starts at the upper-right-hand corner and proceeds, counter-clockwise, until page 16, so it's easier to follow.
Why don't printers do it the same way as the tutorial? The printer's example ends up with all the pages sharing a common spine, thus making it easier to sew the signatures together (plus, it has one less 'cut' to separate the pages). The mini-book tutorial gives each pair of pages its own 4-page signature, which may not facilitate sewing, but it does let you piece out consecutive pages all on one sheet, while regular signatures have highest and lowest page-numbers on the same folded sheet.
Need to see it, to wrap your mind around it? I've made one for the mini-book and another for the traditional signature. Print it, double-sided, with the lowest numbers at the top on each side, and it should line up. Make sure you're turning off "fit to page" when printing. Fold, in half the long way once, then twice, and then in half the other direction. Cut the edges, and you'll have your little book signatures.