Yes, someone in "marketing" and from experience marketers don't mind taking a little "artistic license" with the product they are trying to sell? not a problem, just not written in stone?
I think its like showing a concept car to your prospective buyers/investors while convincing them of your capability to build something close enough to the advertisements. To be very frank, i do not doubt the Chinese ability to turn the 31001 into a beautiful mini Raptor. While clipped wings, and streamlined tails with DSI's and Bubble canopy have been seen in J-20 and do not amount to a huge leap needed for building J-31 as it looks in the advert, the real issue would be the
engines and the second biggest issue would be to build and integrate all the good stuff like 5th gen Radar, Avionics, Software, MMIF, Data Link, Processing computer and so on.