There are four different engines in this photo, each of which appears to use a different TVC mechanism.
Come to think of it, I'm more in agreement with Blitzo now since the baseline plume can vary its shape.
- WS-10 3D TVC, in the demo the nozzle swivels as a whole without changing exterior shape. We have also seen this in a CGI video some years ago. This is different from J-10 TVC's AVEN type which changes shape. I pointed this out in #7,056. However, @Blitzo pointed out that this may be result of a lazy job of the model in #7,058