Complex sentence: The painting was added to the frieze in the dining room at Brøndums Hotel in Skagen which had become the place where the artists frequently met, confirming Marie's position as an accepted member of the Skagen Painters.
Split into simpler sentences: The painting was added to the frieze in the dining room at Brøndums Hotel in Skagen which had become the artists'favourite meeting. It confirmed Marie's position as an accepted member of the Skagen Painters.