When you turn the phone on, Media Scan runs and finds all the pictures in the phone that aren't hidden and don't have a .nomedia file somewhere in the directory path. The apps that use media files, like Gallery and music players, just look in the database that Media Scan created to find what they're looking for (all photos and mp4 files, all mp3 files, etc.) This prevents every app having to do a full scan of the phone every time it runs.
If an app (even one like a web browser) somehow skips putting a .nomedia file in its top folder, Gallery is going to show all the media files under that (it happens rarely). So you get the advantage of a faster phone all the time vs. the mess you got, and have to clean up by hand. (Browsers can download a few hundred individual picture files for one page. That little blue arrow at the right end of the bar? It's a picture. So is the bar. So is the left arrow at the other end of the bar. There should also be a .nomedia file to prevent Media Scanner from paying attention to that folder or any of its sub-folders.)
04-18-2016 06:40 PM