The diamonds can be elongated by repeating rows 1 & 2 and rows 9 & 10 a number of times. This is shown in the border of the shawl in the second swatch photo.
Shown with a cast-on count of 40 stitches.
1 2 3 4 5 Horizontal repeats
1 2 3 4 5 Vertical repeats
Swatch photo uploaded by chrisfourfalcon