It was probably some type of finish/protectant. Although i have never heard of shiny rosewood i am sure your
local music store can get you some stuff to make rosewood shiny. I prefer an oil based protectant/moisterizer on mine. Something like Gerlitz Guitar Honey or Stew Mac's Rosewood Protectant. While they will not make it shiny it will deep penetrate and condition the wood which is important since rosewood is very pourous. So if you can live without shine then a good protectant is what you want.