Constantine Curran:
Joyce at that time [while at university] was a slim and elegant young man, with very blue eyes, thin lips, rather square chin, forehead, as he carried his head always very, in almost an arrogant fashion, with his chin pushed out. A very graceful carriage.
I looked at that photo and the first thing that came to mind was Jimmy Cagney. I could just see Cagney in that pose with his hat tilted that same way.