You did not know? It was the locomotive of the world record holder for speed .. That white rectangle under the side window is the certificate released from Guinness World Records LTD.
I hered about that taurus record, but in my memory it was a diferent livrery, a grey one i beleive with big withe numbers. But probably i am mixing diferent cases
Here you can better understand:
http://www.railcolor.net/index.php?nav=1406157&id=47544&..trait