The theories on how to interpret the devs are many and varied.

I take it to mean that if an item is more likely to be used for magical purposes or in actions requiring magical traits down the line, it would require magic crafstmanship. Craftsmanship for "physical items".

So as a Goldsmith example:
Various gemstones (to use in scepters, rings etc) - Magic Craftsmanship
Various types of hora (Pug weapon) - Craftsmanship

My theory falls apart for items that could go either way, such as casting silver ingots, which could become axe heads or a thaumaturge's scepter.