Here is Seri's shoulder x-ray:
Compared to a normal shoulder x-ray (not Seri). Please note this is the opposite shoulder, and a slightly different angle/view, however you can clearly see the difference in the shape of the scapula.
In the top (Seri's) photo, you can see how the scapula appears to be missing the ends. It doesn't appear to be an arthritic type of change, it just seems to have been put together poorly. Since the shoulder joint is already very reliant on muscle to keep it together, this just means that Seri's shoulder is even more sensitive to muscular soreness and instability than a normal dog.