Slot machines used to be massive, bulky cabinets often topping 40 inches tall...

https://varimail.com/articles/what-is-responsive-design-in-a-mobile-slot-game/

Slot machines used to be massive, bulky cabinets often topping 40 inches tall and weighing hundreds of pounds. Now, these games fit neatly on 6-inch phone screens, making it easy to spin reels anytime without dedicating a whole floor space