Invalid image size. The shorter side of the image must be at least %d pixels long. For more details, see http://sellercentral.amazon.co.jp/gp/help/25601
The image you specified does not meet the minimum requirement for length on the shortest side. Images must meet a minimum size requirement. Otherwise, they cannot be effectively resized for various uses on Amazon.com. Please resubmit your inventory file or product image data feed and reference an image that meets the minimum requirements indicated in the error message.