First of all, this is an awesome idea. Hopefully there’s another vending machine that nearby that dispenses wrapping paper.
Second, why “for Dummies,” when we’re seeing people behind him who probably are not enjoying fighting their way through the holiday crowds?
Comics I Don't Understand 
It’s for dummies because it drastically reduces the choices. These are the presents that, depending on age and relationship, will please the recipient.
Or maybe the recipients are the dummies?
It’s for dummies because he left the house. All Christmas shopping can be done online.
The fact that a joke is stupid and doesn’t work doesn’t mean that you don’t understand it. It just means the cartoonist doesn’t understand reality.
The joke is entirely what it appears. If walking to a store and standing in line and figuring out what stores sells what is too hard, then wouldn’t it be funny if you could just go to a vending machine. The fault that that isn’t *funny*; it’d be wonderful– isn’t with the reader; it’s with the cartoonist.
The “for Dummies” books have done well not because readers actually think of themselves as dummies. The idea is that they put things in simple terms for someone who may not be an expert in the subject. If I wanted to take up basket weaving, I might buy “Basket Weaving for Dummies” because I’ve never tried it. Likewise, the guy in this strip probably hasn’t done a lot of gift buying. The people behind him know how to shop, so they don’t need a vending machine.
Happened to be reading this a few days ago . . .
https://www.cnn.com/style/article/japan-vending-machines-eiji-ohashi/index.html
Mallophobia . . .
https://www.comicskingdom.com/retail/2019-12-10
What MarkM said: “for Dummies” doesn’t literally mean “for Dummies.” In this context it means “made easy.”
Right, if it weren’t understood that way how would any of the many “For Dummies” titles have sold any copies at all? Well, apart from gifts …
I don’t do Christmas shopping any more I gift all year round, if I find something I think X would love, I give it to X. My friends understand, and if you’re not my friend, why am I getting you a gift?
I don’t know where my punctuation went up there; I’m certain as I can be that it was in the post when I sent it.