You will need to install a user script manager extension to install this script.
A clone of the "(mTurk) ProductRnR HIT Helper" script originally by Eric Fraze (Magnilucent). All credit to him for the original code which I only modified.
This script works on the ProductRnR Query Image Relevance HITs. The script will auto-flag all images as "Related", then you can scroll through the images and change flags via mouse-clicks as necessary.
Clicking an image will change its flag. Left click selects "Unrelated". Right click selects "Related". Middle click selects "Image didn't load".