What is that photo in your post ? It looks disgusting
To make Som phak, just leave your vegetable outside somewhere, to let bacteria to start fermenting, when the vegetable is decay and smell almost bad, you can eat it
That picture is not Lao style SomPhak but it's Korean Kimchi which I really like to eat Kimchi b'cos it has very high in vitamin C, good for your stomach as it has Garlic & Ginger too and have good bacteria in there too.
Lao SomPhak is made of Vegetables + Salt+ Khao Niao. That's it. But I like SomPhak Sian the most hahaha...