I had assumed Osram was a British company, as this advert specifically mentions GEC, but according to Wikipedia it was a German firm that sold parts to GEC in the early 20th century.
Wikipedia details some unsavoury aspects of the company before and during the 2nd World War when the Jewish founder and Jewish board members were forced to step down. The company supported the Nazi party in a number of ways, and used forced labour in their Berlin plants.
Osram has moved a long way from those days and is an international company. GEC, meanwhile, is now defunct.
At the time of this striking advert, 1919, all that had yet to happen. It appeared in a short-lived British satirical magazine called Pan and is, I think, one of the most interesting lightbulb ads I've seen.