Herringbone stitch
Herringbone is worked two beads at a time, and each pair sits on the pair below with the beads leaning into each other. The chart keeps the pairs and the lean, so the V that gives the stitch its name is on screen before it is on the thread.
On a square grid a herringbone design loses its pairs, and a diagonal drawn across it will not sit where the beads do. The paired lattice shows which two beads go on together and how they lean, so a chevron reads as the V it will be, and the count by code is what you pick up two at a time.
Word chart
Reads left to right, one row per line, two beads at a time, the way they go on the needle.