You usually preview the email attachments before downloading the files. Actually, these photos have two copies: one in the folder that they are moved into, the others are in Photos Library. You move a patch of images into your Mac and view them with the Photos app. You always make a copy before you edit a file or an image, but do not delete the original one even if you no longer need it. Find and Remove Duplicate Files on Mac with Terminalīefore taking action in removing duplicate files, let’s go through some common situations that you are likely to have accumulated numbers of duplicate files:.Find and Remove Duplicate Files on Mac with Smart Folder.