Jan's right about the border pattern construction. The designer's comment is:
The border is made of a grey diamond pattern on white bottom, which is knitted stranded. Afterwards, the flowers in different colours are embroidered to add the colour.
Other than a short band of garter stitch, it looks like the entire shawl is stockinette stitch. You'll have issues with curling when you make it a scarf. I guess they block the dickens out of it to make it lie flat as a shawl, but the problem will be exacerbated when it's a longer, thinner piece of fabric.
What if you reversed it--took the border and made it the center, with a non-curling stitch pattern at the edges? You could make a gauge swatch, calculate how long you want the scarf to be, and knit the whole thing lengthwise on a long cable needle. Then you could do the black, red, and white stripes in garter stitch, like this photo here: http://weefolkart.com/wp-content/uploads/spring2015/garter-stitch-frontandback.jpg
You'd knit the diamond band exactly as the pattern calls for it, just with more repeats and with a white garter stitch border--say, four stitches wide or so--at each end. Then you'd repeat the black and white garter stitch stripes, and bind off, then go back and embroider the star/flower motif onto the diamonds. I'd use black for the cast-on and bind-off rows, since white edges tend to pick up dirt, and since I hate weaving in ends, I'd cut fringe from all my colors and just knot the yarn ends into the fringe.
Beware, though; scarves knit lengthwise can surprise you when they stretch more than your gauge swatch did. I ended up cutting a scarf in half a couple of years ago, unraveling the cut ends into fringe, and gifting two identical scarves.
The other issue with making it into a scarf is seeing the back. In a shawl, you don't really see the wrong side when wearing it, but scarves tend to twist. It's a matter of preference if you want a scarf to be double-sided or not, but just be aware that can happen.
I'd be more confident about using the embroidered diamond pattern on a hat, mittens, sweater, or something else that does well with a field of stockinette stitch and doesn't show the wrong side when worn. Take a look at the enlarged photo--this would work for a lot of different projects!