Don't know what it means. First we have the 2051 prototype last Dec supposedly the full status J-20 that flew with WS-15. Huitong also think this 2051 could be the J-20B flying with WS-15. Today there's another event of J-20 first flight with WS-15 again? Latest word is today's J-20 with WS-15 doesn't feature thrust vectoring.

According to this source, besides the J-20A with the AL-31F/WS-10C, the J-20S twin seater, the 2051 that flew last year was J-20B. And today's J-20 is a version with 2D thrust vectoring? For now, I'll assume today's is J-20 equipped with non-thrust vectoring WS-15.

Oh well, if today's is indeed a J-20 with non-thrust vectoring WS-15, I'd expect it to complete flight test and enter service very soon. Maybe they just do a short cut to introduce a version of J-20 with WS-15 that can enter service ASAP.

Tiny pix has surfaced. J-20 with WS-15.

A short clip of the first flight.