Have I seen this pattern before in relation to audio?

yes
your guess is cold. if you were looking at this you would be cold too, but it's not ice
Depends on if you were tripping, but probably no.

again, you would not see this in your lines of work.

cooling coils inside a Commercial reefer

getting farther away, zip.

sea sponge in a giant aquarium?

inside of a boiler

wasp nest

he said it's the size of a VW bug.

It is the wall of a root cellar?

ok not a seal ,filter , prolly not Boiler

is water involved ??

No.
Yes.

Is it a sandbox or a pile of mud?

no and no

Deep fried polar bear?

We have a winner!

But here's another hint.

this took a long time to make

Petrified wood