This sign was the first electrical light commercial sign in Oslo, and was first lit up on 23rd December 1909. Since then the light has (according to a Norwegian site about the sign) been off twice, during the war and in 2012 when the sign was restored.
The sign stands on top of a building in the street called Karl Johan, and most Norwegians will think of chocolate when they see it. The sigh is the logo to the company Freia which is one of the most known chocolate- (and other sweets-) producers in Norway. Freia is a part of Mondelēz International, which means that there will be two logos on a Freia product you buy, the Freia logo on the front (very visible), and the Mondelēz logo near the ingredients.