Thanks Dude.
Not quite what I was expecting but very interesting all the same. I see that each finger appears to have an inlet at the base to allow gas flow to alleviate some of the turbulence behind it.
Now to find a picture of a Concorde reheat flame rosette to see how the flame matches up to the finger pattern.
Good game!
Better still, I found a picture of the reheat assembly with the fingers fitted:
Google Image Result for http://heritageconcorde.com/wp-content/uploads/2010/03/reheat-picture.jpg