I actually think this is kinda clever. Not really ha-ha clever, but I think it's pretty neat that he didn't have to mess with the shapes too too much to get a recognizable US shape. That said, this definitely feels like more of a setup than a punchline. This feels weird to say, but I think this would be funnier as a poster. You'd see it out of the corner of your eye and think 'oh, a map of the US', and then you'd do a second take and surprise! It doesn't work so well in comic form because when you log on to xkcd.biz, you're focusing all your attention on it, so you instantly recognize it as incorrect. Maybe Randy could have had some zoom in type thing, or it could have been a multi-panel comic called "the worst classroom in the world" or something.
I should really get more friends who know about programming, solely so I'd have someone to consult on this comic besides my cousin, who is frankly getting sick of me messaging her at nine at night (her time, not mine) just to go over webcomic business. She was, however, willing to tell me "I understand the programming commands, but I don't get the joke" which means I'm not stupid for not understanding this.
As someone to whom programming is witchcraft, this comic could have been written in Chinese for all I comprehend. A quick browsing through the forums and explainxkcd does suggest that there are a couple of mistakes like missing parentheses and such. Also, apparently this isn't a joke, it's just a code Randy made to install any given program.
This really should have been posted to the blag. XKCD has such a history of programming jokes, I can't be the only person who spent half an hour trying to figure out what the joke was before realizing that there actually wasn't one, and not just because Randy tried and failed, but because he genuinely didn't try. Like, props to him for making a thing, but it's not funny, it's not informational, it's not entertaining. So let's put aside the arguments we've had in the past about how XKCD should make jokes that people understand or XKCD should separate the posters and the comics or how XKCD shouldn't make comics that are just Randy exposing his viewpoints. This is straight up not entertainment, no one is going to read this and get any enjoyment out of it. It is not an obscure joke, people who get programming aren't going to find this funny or interesting, it's not informational, people aren't going to gain any knowledge from this, it's not even an argument, no one is going to get agreement chuckles or reblog it on tumblr. This is not entertainment, it is an extra, it is not comic material. If XKCD was an action show, this wouldn't even be an episode that was for some reason just footage of Rachel Ray baking a cake, because that would be interesting to the members of the audience that happened to also like cooking shows. This would be an episode that was just a black screen with audio of the director masturbating.