This one is a lovely red and yellow cloisonne. You can find it in Charlotte's bedroom --

Charlotte's Bedroom

-- but only before you open the puzzle panel in the jewelry box.

How do I open the jewelry box on the left?

After you put the tiles into the front of the jewelry box panel, instead of following the colors, click on all the tiles down the left side, along the bottom, and up the right side to make a big U shape. This pops open a little niche that holds the egg.

And remember, you need to do this before you solve the real puzzle on this box (because you can't access the tile puzzle again after you solve it).