Icelandic designer Jón Helgi Hólmgeirsson describes it:
Jónófón is an acoustic vinyl-record-player that uses a papercup and a horn made out of paper to amplify the music from the vinyl record.
Jónófón strips down a technology that is hidden to most people and copys the design of the classic heavy gramophone. The gramophone that was invented more than 120 years ago by the german Emile Berliner, was a kind of a furniture that played heavy records through a big metal horn. Jónófón however uses a much simpler and lighter form where the record is in the foreground.
You could say that jónófón is some sort of a return to simplicity while the technology today has gotten so complicated that it’s not made for the average Joe to understand. Jónófón comes in a flat-pack and is the user suppost to obtain an understanding of how the player functions by putting it together for himself from scratch.
Jón has a point, one would have trouble building an iPod, but it is easy to see how this works. One should make clear that Berliner did not invent the record player or the horn amplifier; he invented the flat record that put Edison's phonograph, with its cylindrical records out of business. Berliner's records were far cheaper to produce (they could be stamped out) and were easier to store. The horn was the standard form of amplification before electronic amplification, which also let them slow the record down from 78 RPM to 33-1/3, which produces far less volume.
I explained in Amplify your iPod Without Batteries how horns amplify sound.