The system is designed in a way that it works when you link a glamour plate to a gearset. Then the portrait gets automatically updated (when you switch to the gearset).

But of course then you have to go to the dresser every time you want to change your glamour. And there are more jobs than glamour plates available...

Like nobody wants to use it that way. Having portraits update your current gear automatically is what people want, without the link to the glamour plate. It should just show what you are currently wearing. And it already works like that for hairstyles. You don't have to update your portrait when you change your hair.