For my card, I used a vintage clock image from Graphics Fairy and made my own shaker clock. I glued an empty round of small scotch tape on top of the clock image and put some sequins and metal gears. For the cover, I punched a circle a bit bigger than the clock, made a round hole at the center to look like a ring leaving 1/4 inch border to get a view of the clock underneath, covered with transparency and glued this on top of the clock face.
See how the contents inside move when you shake the card. The sentiment I used is from Ginger's House.