Very well possible, however in one of the screenshots it says version 6.3. If im not mistaken windows 8 is 6.2 and following the past couple of version numbering 6.3 would logically be windows 9. Maybe they're changing their version numbering scheme or maybe 8.1 is such an overhaul it's easier to just increase the version number or maybe they're just using it for internal testing. I think assuming these screenshots are legit I would bet more on it being an early stage of windows 9 over windows 8.1.
EDIT: after some googling it appears you're right, windows blue or windows 8.1 is version 6.3