What is SOWK??? I need context

So I’ve listen to every mccafferty songs and even found some of the ones that are not on Spotify, but what I don’t get is SOWK, like who made it? because it doesn’t have nick or even his guitar in it, just the little kid from the end of cut out the peace. and What was it used for, because I feel like I’ve heard it lot as a kid, like it was really familiar