A WebmasterWorld thread has some members who focus on watching Google Image results stating that Google Images is now better at figuring out who the original source is.
One SEO said:
Others also confirmed the change.
I am not sure how many people noticed this or not but I certainly hope it is true.
It is terribly challenging for Google to find the true original source of an image or even content. If they did, at least even 75% of the time, I would be amazed and in awe.
Forum discussion at WebmasterWorld.
Update & Confirmed: Google has confirmed this saying: