There's an xkcd comic where the protag tells someone to make them a sandwich. They respond, "no, make one yourself." The protag then says "sudo make me a sandwich" and they respond "Okay". If you've ever set anything up in unix from the command line, you've run a command only to realize you need to run it as a super user (sudo). The post is scripting that let's you run "make me a sandwich" and "sudo make me a sandwich" in command line, just like the xkcd comic. It's not much of a joke, more of a novelty.