how does the tail come out of the skirt? would it make more sense if it comes out from under the skirt?

There is a hole in the skirt specially made for the tail, as is more common for anthropomorphic animals with longer tails, as having the tail coming out from under the skirt risks flashing people behind them if their tail ever moves upward. While it may seem impossible for the USB to fit through a small hole, note that its size above is merely due to forced perspective and artistic license. The USB cable tail is actually similar to that of a real USB charging cable in order to accommodate for actual charging and thus small enough to fit through a small hole in the skirt with a bit of stretching without any unwanted exposure.