please explain unusual glass speakers Options

[Bartholomew MacG...]

Here's what this page says about these weird glass speakers:

Unlike traditional speakers that project sound in one direction, a sound generator in the base of the Greensound speakers vibrates the glass to project the sound from both sides. Different areas of the glass are responsible for producing different frequency sounds - the curved area at the top produces high frequency sounds, the middle produces mid-range sounds, while low frequencies are produced by the area at the bottom near the base. The use of glass also provides the opportunity for some nice color changing lighting to be built into the base.

http://www.gizmag.com/greensound-technolog/16372/


I was wondering if someone could explain that.