For each result you can see multiple pages that include the image. It also shows the resolution and file size of each version. I did a test search for "bear" and clicked on the first result. It showed 14 different pages containing the same image with different sizes and possibly slightly different crops. You can also select a subsection of the image to search for that.
It makes Google image search feel like an old school internet tool. I know Bing isn't cool or popular, but their image search is undeniably superior.
I don't think we need to blame Pinterest for having indexable content. This is a failing of Google image search for not showing alternate matches for the same image.
Bing has it figured out. I can't tell if Google just doesn't care enough about image search to implement it, or if there's some obscure patent preventing them from doing so.