How do you get you screenshots off the Wii U?
Mid game press the home button on the Wii U gamepad - go to a hosting site of your choice - click browse on the hosting site to look for where the pic is located and the gamepad will then give you an option of a 480p or 720p/1080P screen - on the gamepad press/click/tick the one you want to upload - grab the public link - job done.