Possibly the most curious item yet!
This is the "Segasonic Popcorn Shop". It is a type of strange vending machine found in Japan. It looks complex for a reason. First, you put in your coins (see slot), then you use the menu to choose a type of pop corn. (Salt, Butter, Curry) but then...instead of just getting it, you need to play a Sonic game! The game is in the screen to the right. In it, Sonic has to deliver popcorn, while running on Eggman's treadmill and avoiding traps. You turn the crank wheel (below) and push the buttons to make him run and jump. If you can win the game, it will dispense popcorn into the small door.
With big slightly 3D characters, a colorful presentation, and an actual game in it, this machine is surprisingly high tech and interactive for it's time. Unfortunately, if it isn't used often the product is likely quite stale

Further Facts: It is one of 3 Sonic Arcade-type games released only in Japan. This is the only one that dispenses food. It does not matter if you win or lose the mini-game, you always get the pop corn. If you don't win the game, Tails is sad. Info provided by MetalMandible. There USED to be a Youtube video of this item in action, but it has since dissappeared. In it, you could watch the game and see a demo. If you want to read more about it, SegaNerds posted an article, complete with a quote from someone who got to play it at a zoo. Be sure to Read The Sega Nerds Article.
This is a flattened cardboard cup that the popcorn came in. It's actually rather cute with Sonic and Tails holding their own cups of popcorn.