I suggested wood grain as a possibility, leading to complex but not relevantly specified. Phineas did a Google Image search and came up, ash on ice.
I did a similar search:
This led me to seek to superpose and fit on a colourised version of the suggested original:
This seems to be indeed the source.
In neither case are we dealing with the joint complexity and specificity pattern that leads to inferring CSI thence design.
It is worth repeating the design inference filter as a reference. Notice, the significance of the joint presence of specificity and complexity:
Comments may be made in VJT’s discussion thread. END