Moisture in the air?

The plant reuses the water inside because it is a closed ecosystem, you can find a similar project (without the grow lights) here: http://www.spruitje.nu/projects/big-brother-2/

Actually, after further thought, plants convert water into O² and along with CO² and various elements in the soil, carbohydrates and other plant materials. So, yeah, where DO they get water from? And what about CO²? Is there some kind of animal life in there that eats the plant and poops and pisses?

The water is already in the jar. It's a sealed system.

If you look closer the bottom of the lamp is from some sponge like material which is in direct contact with plant soil. So its probably enough that one twice per week you spray a little water on the bottom, moister will be absorbed in plant over soil trough sponge.

Undoubtedly, the conductive elements are on the inner surface of the glass. The glass will prevent contact were you to touch. Also, only the lamps that are not hanging require this feature. The hanging lamps have the light on the top where external power is applied. Lamps that sit on a surface [such as a table] have their external power feed at the bottom, yet the lamp is at the top. Thus the need for invisible "wires".

Notice that the actual light is at the top of the standing lamp. The cord is at the bottom. The conductive glass is what gets the electricity from the base to the light at the top of the glass.

The electric voltage used for LED lamps is very low, so no harm to touch it, in case of braking the glass.

Undoubtedly, the conductive elements are on the inside surface of the glass, thus the glass will protect those who touch. It's also likely that the voltage is low enough to be non-lethal. Only the non-hanging versions require this feature. The hanging models have their lights at the top where the external power is feed. The ones that sit on a surface, such as on a table, have their light at the top, yet power is fed to the bottom. Thus the need for invisible "wires". There are cords to the lights, because external power is required.

Only the standing lamp has that feature, not the hanging ones