Ebba wears a good example of a late 1880s dress in this photo. So what is the occasion? She was the daughter of a minor officer and a Lady-in-waiting to Crown Princess Victoria of Baden. She ran into Prince Oscar who fell in love with her. Her family was scandalized and forced him to reconsider for two years. They married on 15 March 1888 in Saint Stephens Church in Bournemouth in England by the vicar Gustaf Beskow, who was close to the queen, Sofia of Nassau, in the presence of Oscar's mother, Queen Sophia. According to her Wikipedia article, "It was said that a bridge had been placed between the people and the royal house: 'The Munck bridge,' and the fact that Oscar had to give up his royal title made people say that the king no longer had four sons but only three, as one of them "married and had to quit". When the couple left Stockholm, a large crowd had gathered on the train station to see them off and show their support."
From the University of Minnesota, umedia.lib.umn.edu/node/92989; flaws in background fixed with Photoshop and sepia tone removed by gogm.