It's sensuous stuff, lava. Well, unless you're fleeing from it, that is. The idea of heating wax until it becomes all slinky and sexy was a good one, a great example of an inventor making unusual connections. Unbelievably, until Edward Craven Walker had his lamp related brain wave no-one had ever considered that love making and a red hot solution of molten wax and oil could work together, but work they most certainly do*.
The lava lamp is also of service if you are on the drugs, as you can peer meaningfully into the lamp and conjure drifting, globby pictures out of the wax and your own highness: look, there's a snake, and, ooh, there's a twisted branch and, oh, there's a big, fat orange bell end.
Brilliantly, these images were specifically filmed for 'The Prisoner' - the footage appears as background projections in the main control room.
* Craven Walker was a keen naturist and maker of smut films in his spare time. I have no doubt that he fully understood the erotic potential of his device.