The Nubia X6 name was confirmed by a photo posted via one of ZTE’s official Weibo accounts. There is also a teaser image there, which contains only the letter X, plus a thin handset (silver version) that could be the X6.
Meanwhile, Chinese website mtksj revealed a photo which seems to show the front of the Nubia Z7 / X6. Of course, there’s also the possibility that the Z7 and X6 are different devices, but we can't know that for now.
The rumored features of the Z7 / X6 include a quad-core Snapdragon 801 processor (the same that’s powering the Samsung Galaxy S5), 2GB or 3GB of RAM, a 13MP or 16MP rear camera, and Android 4.4 KitKat with a new, redesigned UI. The handset’s large display may have a Quad HD (1440 x 2560 pixels) resolution.
We should be able to know more about ZTE’s new Nubia handset(s) later this month, thanks to an official announcement.
sources: Nubia (Weibo), mtksj (translated), GizChina