The Hopscotch Floor was released in North America as a sign of the start of school. This was also the first DLC to be a floor which brings signs of newer ones to come!
This is just what it sounds like - a hopscotch floor. Sadly, you can't hop on it, but it does look interesting and is a valuable prize.
The letter received for the hopscotch floor in North America read: Dear [Player's name], The first day of school is right around the corner, which means it's time to brush up on those playground games. Maybe this will help! Have fun! Nintendo