I just updated from El Capitan to macOS Sierra and I found a problem with preview.
As you can see, the image is embedded in the PDF because you can see it in the thumbnail. Also, when I use the magnifier, I see the image.
I can reproduce this with other PDF.
I restarted my computer but it's still not working. I was told to repair the permissions under Disk Utility, but still not working. Do you have an idea to fix this?