Mon Tricot: 1500 patterns, p. 104
The YOs are knit on the wrong side to create deliberate purl blips on the right side. I think this is the thing which is being described as “horizontal”. - gannet
Shown with a cast-on count of 14 stitches.
1 2 3 4 5 Horizontal repeats
1 2 3 4 5 Vertical repeats