I'd never seen one of these before I found this, but have since learned that "slip animation" magic lantern slides were a Victorian era novelty. Inside the wood frame are two panes of glass, one of them which, painted with one strategically placed black blob, slides in and out to either conceal, or expose, the popping of the cork on our lady's bottle of ginger pop! Pretty clever, and I really love the analog method of simulating action. And tis the season (well, really, tis always the season!) for popping something. Happy New Year!

7" x 4" x 3/8". Good condition, with some craquelure to the image as evident, and structurally in great shape Held up to light, one can see through the black blob a bit to what it is concealing, but placed against a dark background the trick works great!