He's short and fat, but he's not supposed to be that short and fat. The image's x-y ratio was altered.
Could produce an image with some padding to avoid the problem, but the general fix is probably to file an issue on it until kbin gets a patch to permit proportional thumbnails.
Could produce an image with some padding to avoid the problem, but the general fix is probably to file an issue on it until kbin gets a patch to permit proportional thumbnails.