-Kiku-

welshdog said:

How does the ethernet signal get transmitted to the Mac from the power block? Is it fiber optic inside the cable? Still copper wires?

I would like to know, too.

There is an easy way to find out, but it's not practical - disassemble the power adapter and cut the power cord to see what's inside.  Obviously, no sane person would do this to their brand new M1 iMac.

The alternative is to ask those 'geniuses' working at the Apple Store.  But we already know the answer - they don't know.  And they're no geniuses.

And so the mystery remains... Perhaps someone in this forum can navigate the Apple customer service menu and connect to an Apple engineer?