A little portable piano
The laterna is a barrel piano which is indeed a little portable piano with an action activated by a wooden cylinder which is pinned with several thousands little nails; every nail being a musical note.
Mostly forgotten in the west as it was replaced by disc operated music boxes and player pianos, it was the main music reproducing instrument in Greece for almost a century until WWII. Therefore it was extremely popular, massively built and greatly adored by Greeks. It did in fact played a vital role in the evolution of the Greek 20th century popular music. Old generations remember its glamour and glory-newer generations see it as a begging tool and the young generation shows an enthusiasm with true curiosity and respect.