Nintendo codename “NX” icon first revealed: once the Switch code
The icon and startup animation of the Nintendo Switch prototype, codenamed "NX", were taken from the initial version of Mario Kart 8 Deluxe.
"NX" is the original codename for the Switch, which was first mentioned publicly by Nintendo in March 2015 and remained in the background for more than a year and a half. Nintendo did not officially announce its name as Switch until October 20, 2016, before any image information of the machine was made public.
The tweeter "Paul Kelly" found the "NX" icon and startup animation in an early version of Mario Kart 8 Deluxe, and the interface shows that the prototype was built on Oct. 18, 2016, two days before the Switch officially announced its new name.