Never mind the fractured English - these passthrough piggy-back plugs, called “Infinite USB”, are clearly a work of genius.
The only problem, really a very minor one, hardly worth mentioning, is that each of these cables is presumably a two-port bus-powered hub. And the USB spec forbids plugging one bus-powered hub into another one.
The official specs for USB also prohibit plain extension cables, mind you, and most extension cables actually work fine with most devices, provided you aren’t greatly exceeding the five-metre cable-length limit. And, similarly, in reality you often can plug one bus-powered (or “passive”) hub into another and have it work, more or less. You may not be able to use all of the ports - which is less of a problem if there are only two, of course. And you’re quite likely to find you only get a USB-1-speed connection. But passive-hub into passive-hub will usually sorta-kinda work. Especially if the powered port your illegal chain of bus-powered hubs is plugged into can deliver more than the half-amp of current that the USB spec says it should.
The reason why daisy-chaining passive hubs works at all, by the way, is that many bus-powered USB hubs report themselves as being self-powered. A real self-powered hub is one with its own DC power supply, which allows it to deliver the full 0.5A of current on each of its ports. But there’s nothing, except the ethics of the manufacturer, stopping a bus-powered hub from declaring itself to be self-powered, whereupon it’ll at least attempt to work if plugged into another passive hub. A passive hub that admits that it’s passive won’t work at all if you plug it into another, similarly-truthful passive hub.
(Most self-powered hubs will work even if you don’t connect their plugpack power supply, but they’ll only be bus-powered when the power supply is not connected. I wonder how many of them report themselves as bus-powered when the plugpack’s not plugged in?)
I’d be pretty surprised if even the green-striped #3 one in the above picture worked, though. I’d bet money that the apple-cart would have been thoroughly upset at least by the time you plugged the #4 grey one in. Oh, and if the Infinite USBs reported themselves honestly then, of course, none after the original #1 blue plug would work.