Sometimes it won't show up because the file type is wrong. Make sure the head, body, tail, and eyes are .jpg or .jpeg. If you have a mane, that is the only one in which should be .png. Sometimes I forget to make the files the right type and that's why it won't show up. And as Ramine said, if may have something to do with the .mat file. If the codes are off by a single letter or character, it won't show up at all. Hope it helped.