if im not wrong you can upload any photo from the wii u

you need screenshot plugin on wii u and app called wiiUshell but if you are on 3DS you can't do that

i only have a wii u, so if that is what you are on, you have to be in the game, hit the HOME button, then the miiverse button, go to the community, post, and then their should be a picture button. Click that, and you got it