I'm Richmond Marquez, my device is Asus Zenfone 2 E551ml. I frequently encounter that my photos are duplicated when I'm posting photos in social media apps such as Instagram, Facebook and Viber. The export album in the gallery duplicates a copy of photo that I post and it consumes more storage of the phone. So i suggest that you should apply a fix for this, not only because it is necessary but of course to help us conserve and manage the storage.