How do unsolicited photos appear on S7 photo gallery?

[AC Question]

In Samsung s7 Unknown photos have appeared in photo gallery

 

[B. Diddy]

Welcome to Android Central! What are the images of? They might be images that are being cached by an app. A good app developer will know to add a ".nomedia" file to the directory where the app caches images, which prevents the system from adding those images to the Gallery database. So if the dev forgets it, then you get these images showing up in your Gallery.