Images were from the previous owner and weren't removed before the device was resold.
Refurbished gadget are great if you don't have the money (or just don't want to spend the money) on pricy gadgets. Generally more reliable than buying second hand, you can be sure the device has been wiped and tested. Not only that, but the retailer selling you the refurb will also replace anything that isn't up to snuff (such as the battery). However, it doesn't always go so well.
Earlier this week, we heard about one Amazon customer who ended up with a stolen iPhone and it seems he wasn't the only unlucky consumer this Christmas. According to 9 News, a 5-year-old in Colorado found porn on the second hand 3DS his dad bought him for Christmas. Mark Giles bought his son Braydon a refurbished 3DS for Christmas. The device in question was purchased at GameStop. Unfortunately, it seems GameStop wasn't as thorough as it should have been about wiping the device before reselling it. Braydon ended up seeing the nine graphic images that had been left on the device.
The discovery was made when Braydon asked his big brother to help him delete some photos on the 3DS that he hadn't taken. His brother saw the pornographic images and told their dad, who immediately called GameStop. GameStop was apparently apologetic and gave Giles a new 3DS for his son, as well as several games. GameStop corporate told 9 News that it was looking into the situation, too.