She's just describing the yo and slip st as a sloppy diagnonal loop. Telling you what it looks like, there's no such stitch as such. Do a google search on Brioche - you'll find examples of it, though I'm not sure there's a picture of how it's made. And I find it much easier this way - k1, k in the stitch below, k1 etc on all rows. Look in the Abbreviations sectins for how to k1B(below).