it doesnt play the instrument, its a sex toy for the geetar(vibrator), to awake the physical properties in wood and make it experienced like old timer...
anyway, its in the product description page as well, written in a more polite way.
The wood tops (soundboards) of instruments contain lignin (also spelled lignen) http://en.wikipedia.org/wiki/Lignin Lignin acts like a torsion box between the hard winter lines and soft summer lines of wood. The instrument’s vibrating strings cause lignin in the top to “relax” and “loosen” by defined parameters of motion, subjectively improving the instrument’s audible performance vs. its prior state of being tight and stressed. “Play-in,” “run-in,” and “seasoning” describe the relaxing/loosening process. Instruments new, recently serviced, and not played regularly benefit from play-in. We have noticed even guitars played regularly improve after a half hour or so of use.
I did ask about that actually.. apparently it's nothing so strong that'll cause any harm.. it's not to different from how it is when you strum and play. Anyway the vibration strength can be controlled too.