Deleting Pictures through adb - Yet They Remain in Gallery
The reason the pictures remains visible in the Gallery is because the Android's MediaScanner is a bit weak in this regard. What happens is this - when Android boots up, it runs the MediaScanner, which goes off and checks all the images, ringtones, audio to sum up, and keeps tab on it. This is only done once on boot. 

You can get around this, by unmounting the SD Card, do this safely (Settings > Storage > Unmount SD Card) this will take a few seconds, once its unmounted, you can pop out the SD Card, pop it back in again, this in turn will force the MediaScanner to run again, and then all the images that you've deleted are no longer there in the Gallery.

MediaScanner is a service that acts as a caching service in that it caches all media (images/audio). On some ROMs, there is a facility to force it to run again without having to do the above.