Slot machines used to fill entire casino floors with massive cabinets over 40...

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

Slot machines used to fill entire casino floors with massive cabinets over 40 inches tall. Today, much of that action fits comfortably on a 6-inch phone screen. This shift means you can spin classic reels anywhere without a trip to the casino