You're not seeing double. Both these screens belong to one phone, the ZTE Axon M. Available on AT&T in the US for $725 (which converts to about £538 and AU$953), this phone features two displays that fold out.
In the US, the Axon M is an AT&T exclusive. At about $725, it also costs about the same as some flagships now like the Pixel 2, iPhone 8 and Galaxy S8. For more info, read CNET's review of the ZTE Axon M.