Delphigirl
I think it is a commentary on the fact that Kate is no more than a cypher for people to hang their own thoughts and expectations on.
That may be the case. That's up to the artist. I'm sure Kate didn't put herself forward for that, but many people see many public figures in that way.
She has never done anything or achieved anything save the birth of three children
Fair enough, lots of us have done that (only two for me).
Still, I felt it a personal achievement. Many people have felt it an achievement to have birthed children. I don't think she’s said claimed it as a particular achievement? You may know better than I.
she appears to have no interests (or none known about)
See Serenster's list.
Try reading it without being childish and picking out one thing and saying "Ooh! She keeps bees <snigger>".
she barely speaks and is incapable of stringing a sensible sentence together in public,
Really? Seemed totally coherent when I've heard her speak.
her role is to dress up and wave,
Yes, true. Like many other public persons being is part of her role.
At least she has a role.
her photos are airbrushed so she is almost unrecognisable
I'd say not. I think I could recognise her normally, I think.
But not from this portrait.
is this not a commentary on that? She is a flat, boring, image projected to the world without any identifiers save status.
I'd say she's not a "flat, boring, image" [sic] any more than any other famous person.
Hell, we don’t at the moment know whether she is conscious or in a coma and the public don’t seem to care.
Should we know?
And I think many people care - not because she's the Princess of Wales, but because they're human.
Anyway, I'll leave you to the one interest the public know you have: posting on the internet.