#6

Here we can see someone suggesting a so-called “food hack.” The idea is that if you don’t have taco shells, you can just use tortillas instead. At first, this might sound like a clever or helpful tip. However, once you think about it, you realize that taco shells are essentially just tortillas anyway—usually the same thing, just folded or fried into a different shape.
Because of that, this isn’t really a hack at all; it’s just stating something very obvious. That’s why the person below replies with another “hack,” suggesting that if you don’t have ice, you should simply freeze water. This response is clearly sarcastic and is meant to mock the original suggestion by pointing out how unnecessary and obvious it was.