There is a new Google manual action Penalty named "Image Mismatch"
What this new penalty from Google does is checks to see if the image on your web page matches what is shown in Google Image search results. It is a form of "Cloaking" but is not mentioned by Google as such, but it is. It is when "your site's images may be displaying differently on Google's search results pages. than they are when view on your site."
How to handle this if you receive a notification1) Be sure that the images that your site displays are the same as what they are in Google's images results search engine. 2) Make sure that you've corrected the images and that they are exactly identical when they are viewed either on your site and in Google's results and then request reconsideration from Google to get it wiped out.
The reason Google is doing this is to give the best search results possible and this is just one more step towards a spam free web.