I am not much of an expert. But the air intake is different, also it has what looks like a fixed tail wheel.... (the lower engine cowling maybe has just had a field repair).
......I'd prefer to wait for the people who are better at this than me.
The short carburettor intake was also used with the early PR XIs as well as the rounded tail. But you are right the fixed tail wheel says that's the PR IX. The Spitfire PR IX was very similar in appearance to the early PR XI and is confused with it very often. Also the lower engine cowling is more characteristic for the earlier PR Spits. As memo serves the PR XI got it shaped with a different way ..