Admittedly, I also always thought the established marque, while lovely, doesn't quite work with the description. Here's a refresher for you all:
"With some effort, I recognised the underlying design, which was based on a very old pattern, the briar rose. Somehow Master Tielhard had kept the dramatic vigor of the archaic lines, yet infused them with a subtlety that spoke at once of the vine, the bond and the lash. The thorny lines were stark black, accented in only a few choice hollows with a teardrop of scarlet - a petal, a drop of blood, the mote in my eye."
-Phèdre no Delaunay, Kushiel's Dart by Jacqueline CareyBearing that in mind, the first indicator of the look is the fact it takes Phèdre effort to actually discover the underlying floral arrangement of the design. Here are some wonderful versions by other fans that I drew on for inspiration during my research process:
Both of these examples are by Elegaer on DeviantART
EDIT: Thanks to Google 'search by image', I've finally located this cosplayer here! I found this version via Tumblr, but don't know the cosplayer/photographer. If you know them, please comment so that I may properly credit them! The curling vines in this version really stood out to me as truer to the 'briar rose' inspiration.
I went through a few iterations, some which swung wildly from a very literal rose bush and others that went more abstract. In the end, I decided to keep it simple and to preserve the flail 'tail' of the original design (with some slight modification) because it feels to me like the perfect representation of 'bond and lash' all rolled in to one.