Known since October 2021 on satellite images, this is suggested to be a (full) ? scale mockup or even a 6. generation technology demonstrator built by 611 Institute/CAC featuring a tailless diamond wing configuration. And today this ... Just a CG or indeed the rumoured testbed?
(Image via @沉默的山羊 from Weibo)
maybe a technology demonstrator to check tailless aerodynamics (like the X planes in the US system?)