Google have released information about a new Google penalty that is name the “image mismatch”. This is manual action and is given to sites that the try to change or manipulate the images found that are indexed.
Google have been helpful here and provided data.
If you have received this it may be due to something unintentional such as using hotlink protection preventing users stealing your images or it maybe due to cloaking images.
If you receive this manual action you have to correct the problem and ask Google to reconsider your website.