I downloaded and installed the Samsung PC Share manager.
It does nothing special.
The "Video", "Music", etc, selections on the TV are client side filters for recognised MIME types using extensions.
That is, when you choose "Video" on the TV, if you look in a folder with both video (say MKVs) and audio (MP3s), then you don't see the MP3s, only the MKVs. Rinse and repeat for audio, etc.