Here you can see a General electric NE-32 sign/pilot lamp. These lamps were mainly used as pilot lamps or nightlights.
These lamps are intended to run directly of 120V mains with a build in ballastting resistor.
Tese lamp have a high surface electrode consisting of a coil for one and an upside down seat metal pot for the other one. Unlike most other discharge lamps, were a discharge colour is formed and terror the light is produced in a panel between the electrodes, these lamp only present a corona style discharge around the electrodes. Therefore the light output is directly proportional to the surface of the electrodes. Tis allows to also make listed symbols in these lamps for decoration. One of the best known examples of this is the 1952 commoration lamp for the coronation of HM Queen Elizabeth the second. However there have also been made lamps with religious symbols, Letters, and even striplite type lamps with entire words or small sentences.