There was nothing in the video audio that identified what weapons were used.
The bases I used for judging height was based on the fact that the videos appears to have been shot from the ground, so to get that kind of definition, the J10 could not have been flying very high.
All LGB release videos I have seen have been shot from other chase aircraft.
As for dumb bombs, well you might be surprised at how accurate they can be at low altitude with modern fire control radar. I remember seeing clips of F16As bullseyeing tanks with dumb bombs. And this was in training as well as operationally during Desert Storm.
The problem is that in order to get low enough to have a good hit probability with dumb bombs would also place the plane within the kill range of most MANPADs and mobile AAA. The biggest advantage of LGBs is that they can achieve better accuracy from much higher altitude, thus reducing the risk to the plane without having to resort to carpet bombing to take out a target.
Now, the first photo posted by Deino already proves that J10s are LGB operational, so whether this particular video is actually the one that showed the use of LGBs is rather immaterial.