I don't think I'm reaching by saying the standing cardbox is too much and that more importantly is a lot cheaper than the magazine tactic to take down a guard
Same effect, different ways of achieving it.
Humour me a moment:
Let's take what happens in MGS as the rules of its universe for a minute. The MGS universe is one where magazines or just posters featuring pictures of just about anything (mainly beautiful women) are capable of distracting guards to the point that they will not notice anything else around them.
You have no problem with that, right? Even though sometimes you just have to show a hot lady on the TV screen of a tiny Metal Gear to distract people... or that, heck, some magazines can make people feel specific overwhelming emotions. Regardless, you are okay with the effect that magazines and locker posters and what-not can have on people, yah...? Because otherwise, I don't know how you put up with the series this long!
Okay, so we also know that in the MGS universe, every cardboard box is capable of hiding a person in it. You're okay with that too, yeah? Not too unrealistic....?
So let's take the next logical step: In the MGS universe, it doesn't take the kind of genius who put cameras and telephones into one hand-sized box to realise that you can combine the properties of magazines/locker posters (which inherently distract randy men) and cardboard boxes (which hide sneaky men) into one handy device. It is, in the context of the MGS universe, a logical evolution. It is such a logical evolution of the technology that it would be unrealistic (in the context of the MGS universe) to
not combine those two technologies.
YOU'RE WELCOME
