These are internals of actual equipment. We buy items, usually via eBay or Craigslist, and we take them apart. Sometimes this requires special tools. Then we photograph the pieces and meticulously render them in Adobe Illustrator. Troy Paiva and Garry Booth are two of the skilled artists who have ‘exploded’ designs for us.
This Mac design is great, but, as I’ve said before, I’d really like an Apple IIe shirt.