OK, I am officially obsessed by Princess' Anne's shawl. Went on a crusade to find better photos . She got a lot of press the next day at Ascot for wearing the 35 year old outfit and this shawl got scant attention.
http://princessmonarchy.eklablog.com/royal-ascot-2015-2eme-jour-a117944062
There are 3 good shots, one shows the corner, the other shows her from the back , the last from the front
The jewel in the corner lacks detail, shading, and the corner shot shows the thin material - cotton voile perhaps ?
The photo from the front shows the drape of the fabric is bad, it does not have soft folds even Hermes cotton drapes better, and a silk blend does wonderful. OK, not everybody drapes a scarf as well as Mai Tai - see her blog for photos of the real B&W 90cm Femme aux Semelles
The tiger stripes from the back side - oh dear, very badly done , coarse looking
It is certainly not a bespoke Hermes scarf, and pareos are rarely done in THE MAJOR designs , pareos are not square and the carre designs dont work, so, you see other lesser designs in pareos