the trailing edges not aligned for stealth reason, the outline of the frontal section blurs alot more than the seemingly unnaturally clear trailing edge. I'm leaning towards fake.Interesting theory and indeed not unlikely given how often we have been fooled recently!
By the way, could it be that "X" is down right now?
If real, it might even be refined version of j-36 which means j-36 we'd seen has been flying for quite sometime and brought out recently to beat the deadline of celebrating the ccp anniversary. Now we see a more refined version making maiden flight.
This isn't unprecedented, as Turkey KAAN 1st prototype (0) is said to differ alot from the 2nd prototype in the making.