One of its unique features is said to be its controllers which are apparently detachable, but since it is just a rumor, it’s hard to say if that is the real deal. However according to a recently discovered patent by NeoGAF user Disorientator (via Nintendo Life), it seems that there is evidence pointing towards the rumors being true.
As you can see in the diagram above, it describes how accessories can be attached/detached to the console. The patent description reads, “There are conventional accessories which, when connected to a portable device, add functions to the portable device. For example, there are techniques where an external controller as an accessory is connected to a connector provided on a controller of a game device. This enables a wider variety of game operations using two controllers.”
However we should note that the diagram in the patent looks very different from the mockups by Eurogamer posted last month, but then again these are just rumors for now so who’s to say they were even accurate to begin with. In any case Nintendo is expected to share more details about the NX later this fall, so hopefully we will find out more then.