From fripperiesandfobs.tumblr.com/post/147648683142/ceremonial-dress-of-magdalena-sibylla-of-prussia.
Here is the dress seen in this image from the back showing the skirt decorations in more detail.
Keywords: Magdalena Sibylle von Preußen, Prinzessin des Herzogtums Preußen, Kurfürstin von Sachsen, Princess, Duchess, Hohenzollern family, Wettin family, German, tabbed fitted bodice, collar, tabbed long close hanging sleeves, cuffs, long close false sleeves, full skirt, rosettes