The culture of Friendship is Magic is really all over the place. In terms of aesthetics, you have classical Greco-Roman in Cloudsdale, medieval Near-East in Canterlot, Old West in Appleloosa, medieval Central European in Ponyville, Art Deco in Manehattan, and something completely unheard of in the Crystal Empire. Technologically, there's a smattering, as well. Stuff like quills, velum paper, etc., are all pre-Industrial Revolution. Trains, cheap stainless steel, and rolled printing presses are all late 19th Century, but there's actually a lot of mid-to-late 20th century stuff, too, like the hydroelectric dam, the battery-powered flashes on the compact cameras, everything about Vinyl Scratch, and the construction equipment. The material culture of MLP is definitely more a tool for the show's whimsy, than a hard-and-fast element of the world-building. This is unfortunate, since the roughly Industrial Revolution tech level was apparently part of Lauren Faust's intent, but even then, she acknowledged that reference to modern technology was acceptable for gags. As time has gone on, the tech level's value to world building just wasn't that great, so gags took control.