Once a pic has been sharpened resized and many different people have saved it and reposted the artifacts are created make it hard to tell, but yes you can look at it in photoshop and be able to tell to a certain degree if it has or not.
Just to add, you can see the blue come through the squids body.
The degradation of a photo after saving 20 times is incredible. Here is a pic that I found of Camshaft and I saved it a few times in JPEG , you can see the same holos forming around him just like it the pic posted.
Original,
As you can see ,there is an out line around him due to pic being resized and saved many times, it is the same thing that is happening in the squide pic. Sorry to use your pic Camshaft, but I needed something you were familiar with.