Delete Xbox pictures?

First of all I would like to mention that I just sold my Xbox. Back then when I was very little I played a lot on my XBOX 360. Every now and then, recordings were made from Xbox Kinect. I have now completely deleted the memory unit. I also removed all profiles. It's not possible that there are still pictures, is it? In addition, I'm not sure whether any images are stored on the disk. Can someone enlighten me there?

If you've set it to factory settings, nothing should be left on it.