Duplicate Sets are groups of two or more images that Photo DeDupe has flagged as duplicates. You can review each set in the list view or double-click on a photo in the list to view a larger version.
From the single image view, toggle between each copy of an image to determine which one you prefer to check for removal or deletion.
View more information about each photo and compare metadata by clicking the info icon 
at the top of the right sidebar to reveal the right panel and access the Info Panel.
Post your comment on this topic.