Yeah I think this is one of those need to wait for better pictures cases. There’s definitely *something* going on with the J-20’s engines though.
My impression is that something was up since early/mid 2021 when the rumours of J-20 testing with WS-15 became very punctuated across the board, and then we got a couple of blurry pictures about that time (included in Deino's excellent compilation image).
Since then we've gotten more blurry images, all seemingly depicting a similar configuration of a J-20 (likely an early 201X prototype) with the right engine notably being different from the left with a shorter/different nozzle... and all with ambient but persistent noise about J-20 being tested with WS-15.
Our modus operandi for confirming milestones for new engine types is one of caution, and the threshold is a bit higher than for other products, which is why we definitely can't just go out and say that "this is WS-15" because the images just aren't clear enough nor consistent enough, nor do we have insiders straight up coming out and saying "this is it".
But at the same time, there's enough noise and consistency from these pictures (even if they are very blurry, and even if one or two of them might be doctored), for us to seriously consider the likelihood that this may be WS-15.