Saw this blog post tonight, and I have a good guess Melvin Yoder's machine shop looks a lot like this woodworking shop:
Amish Stories: A factory tour of an Amish wood working business. Lapp's wood shop
Different Amish groups & church districts vary on how what technology they adopt. This group looks like they prefer air; I know of other Amish businesses that will use electricity for the business not home. My guess is they have an electric-start gasoline powered compressor behind the building so it runs automatically to charge the air tanks without someone running outside all the time. And they don't mind the guy having a website. (Years ago there was an Amish draftsman who I posted on some of the same websites with; he had access to the internet at his job where he had to look up information from suppliers on the web).
They're also mostly using natural light, I've seen pics of other Amish shops & stores like that -- but you'll notice in the pic before the one with the dog, there's a pair of propane light mantles on the left hand side.
Is an interesting side benefit of using air powered instead of electric powered tools in the shop, they've setup those little water jets you usually see used on CNC mills to wash away metal shavings to instead blow air to remove sawdust.
Lot of Amish businesses these days. They're just breeding too darn fast to find enough farmland that suits their farming and family/church life styles. Doubling in population every 20 years, and about 80% of those born to Amish families chose to stay in the Amish church. Saw a story on one of the blogs the other day mentioning an Amish woman who had 104 Grandchildren, and I don't think that is terribly unusual for them today.