The posters who make the point about business dress are right.
There are dress codes in the City if you are in the financial sectors or law. Usually suits for women, smart dresses or skirts and smart tops in subdued colours.
I see being a Minister in that same category. She is representing us in meetings and the UK. She has to look formal and 'together' because people do make judgements on appearance, like it or not.
Has everyone forgotten Michael Foot and his donkey jackets? He was ridiculed at the time.
The idea is that the clothes create a neutral background and are not shouting ME - LOOK AT ME by being shabby, loud or too casual.
On a personal level, her face is not 'young' and her hair and glasses are very old fashioned as is her make up.
When she wears dresses they are often too tight- a size too small- and she looks 'all boob'.
I am sure it's all deliberate which actually says a lot.