This gold egg was inspired by the interior of Maria Feodorovna's favorite palace - the Anichov Palace - where many of the ceilings are painted en grisaille.
On pink enamel panels designer Vasilii Zuev painted miniature allegories portraying the arts and sciences - after originals by Francois Boucher - in cameo style. The egg is also decorated with rosettes of platinum-set diamonds and seed pearls, and is lined with velvet.
The surprise has been lost, but in a letter to Queen Alexandra of England Maria wrote: "Mr. Fabergé himself has brought me this most beautiful egg. Inside is a sedan chair carried by two blackamoors with Catherine the Great in it, wearing a little crown on her head. You wind it up and then the two blackamoors walk: it is an unbelievably beautiful and superbly fine piece of work. Fabergé is the greatest genius of our time."
This similar piece - also made by Fabergé - might give you a sense of what it might have looked like. It belongs to the Forbes Collection, and was for a long time thought to be the missing surprise. That idea was given up when it was discovered this automaton didn't fit into the egg though.
Here is another example of how the sedan chair could have looked. Catherine the Great was a great patron of the arts and sciences, and so fitted well into the egg's design.
The "Catherine the Great Egg" can now be seen at the Hillwood Museum in Washington D.C.