The difference between "MagiCube" and "Flashcube"
If you examine the base on a MagiCube you'll see that the connector is slightly different than a regular flashcube, and that they don't have any contact wires either. The MagiCube is fired by a mechanical pyrotechnic device instead of an electric charge. Look closely at the little openings in the base, and you'll see a silver wire inside. This is a spring-loaded striker. A sort of tab comes up out of the camera body, and slips this free from a sear. It then strikes a single thick wire that protrudes from the bulb base, and the impact fires a little charge that sets off the bulb.

The cameras that use MagiCubes will generally either say "MagiCube" or "X-Cube" somewhere near their cube socket. They also won't have any electrical contacts in their soecket. Pyrotechnic flash cubes will generally have some sort of large X design on the top of the cube.