Sarah Greene's shirt on the finishing line.

[Imtoooldforallthis]

Does anyone know where its from?

Think it’s Boden. Some availability…in small sizes.
https://www.boden.co.uk/en-gb/silk-shirt/sty-t1110

Sorry - that link won’t bring up that shirt. Try searching for ‘silk shirt’ - ‘multi, textured ikat’. It’s in clearance.

https://www.boden.co.uk/en-gb/silk-shirt-multi-textured-ikat/sty-t1110-mlt

That's it, unfortunately non in my size.

There's some on the Next website https://www.next.co.uk/style/st593735/897842#897842

It’s also on eBay in various sizes