Are you sure that's a production plane and not an older picture of one of the prototypes ? And can you tell from the angle rather the plane is using the AL-31 or a WS-10A ?
If it is a AL-31 that raises two questions. Since the AL-31's that China has are not special versions for naval ops to deal with the salty sea air those engines wouldn't last very long. And the second question is what does that tell you about the WS-10A ? That they would rather use a plain AL-31 then a specialized WS-10A for their naval fighters. And can they actually take apart the AL-31 and sprey it with a protective coating against the salty sea air ?
How can we know what will be J-15´s production version? They are still in prototype phase.