Plaited herringbone stitch is used for the half of the body of this vase, but it is a non-standard way of tubular plaited herringbone stitch, that is picking up two seed beads at a time.
Picking up two seed beads at a time is the same as using a long bead such as a fire-polished bead and a bugle bead, and it will cause showing unsightly threads between the beads. Unsightly thread became invisible by adding extra beads.
This way is also used for "Decorative bottle with a zigzag pattern".