Give your Mii a 3DS as a gift and you might see him or her playing Tomodachi Life on the unit. Give the gift of a Wii U instead and your Mii might play the ninja mini-game from Nintendo Land.
When you are playing Quirky Questions at the Observation Tower, you will have the opportunity to fill in the blank when the question "Who likes ____?" is posed. If you enter Sony or Microsoft, none of the Miis will raise their hands. That's because Sony and Microsoft are Nintendo's competition.