Alright, so it was a bit obscure, but I had two whisky glasses in my kitchen cupboard, a large straight one and a small curvy one, one inside the other... and they made nice patterns together :)
So, decided to try to make it into a mystery macro and add some colour, courtesy of some blackcurrant cordial in the large glass :)

"Make mine a double" - two whisky glasses. So blatantly obvious. Errr, ;-)