This interesting thing is a Fruit Machine.
A Fruit Machine is similar to a Slot Machine, but it is found only in the UK. You can put money in, and win it back too. They're found in arcades, and may or may not count as gambling devices. (Some countries, like the USA count certain things as 'gambling devices' which are only legal to be placed/played in certain areas, such as Las Vegas etc.)
As the photo is nice and large, you can see the various places on the machine which light up according to how you're winning along. The Sonic picture goes into a run, then a spin, followed by a trail of numbers, words and little pictures which likely light up when the machine is played. You can see "15 Pounds", "Loop Loop", "nudge spinner" a ring bonus, a ring chart, and the three wheels in the center for play.

The buttons let you do things like spin, bank, collect and bet various amounts on the wheels. It plays the Green Hill Zone, and Sonic 1 & 2 opening songs, also it has the sound effects from those games. While obviously not as high-tech as current slot machines this one is still a great display of classic Sonic styled action and art.
Because machines of this nature are not for home use, but rather as "appliances" in gameing areas there likely were not that many produced, add to that the complexity and size, and you really have a rare and exclusive item.