Are you extracting the files from the zip as well, or are you running it from inside the zip? Running the index file while it's still inside the zip will result in the images not showing.
I haven’t tried since yesterday but I might've tried opening them without unzipping the file, though I also tried to unzip it afterwards and couldn’t get it to work with 7zip. (Though knowing me, I most likely didn’t do it the correct way)