Interesting. It appears that the US version of that photo is faked. The USB port is on the other side of the device.
This review has photos of the top and bottom of the device taken from angles that clearly show the difference between the USB port and the power button:
Kindle Oasis with LTE (This is the second generation device but I believe that the port position is the same in the third generation device.)
(Added: Photo from review attached. It is face down, but shows the same end as the stock photos.)