Look at the last few years of official events at the Spanish court and one cut repeats itself to the point of tedium: the trouser suit. Queen Letizia wears it, Princess Leonor wears it, and that is not a coincidence of taste but a decision with deliberation behind it.

The suit has a longer and more interesting history than its present-day dullness suggests. The first models - jacket and skirt - were proposed by the British designer John Redfern in the 1880s. They were more comfortable than dresses but kept the silhouette of the era. The twenties brought relaxed cuts and soft tweed from Coco Chanel. The real turning point came in the sixties, with André Courrèges and Yves Saint Laurent - and especially in 1966, with Le Smoking, the women's tuxedo that trampled the rules about who was allowed to wear what.

Why the suit specifically

The suit is traditionally tied to masculinity and to power - the businessman, the politician, the diplomat all wear it. There is also a prevailing belief that women in those fields have to look masculine in order to carry authority. Communications expert Cristian Salomoni does not think that is the reason behind the Spanish court's choice.

His explanation is more concrete and more interesting. The suit is translatable: its formality shifts with colour and fabric, and accessories change the impression entirely. It fits into different protocols without drawing excess attention that might "overshadow the political message through the styling". And, as Salomoni puts it, it avoids "sexist interpretations that could arise from the length of a skirt or from a neckline".

Here we are on very concrete ground. This is not about aesthetics, it is about calculating how much of an event's coverage goes to what a woman said and how much to what she wore. Anyone who has followed politics at home knows that calculation is not a Spanish speciality.

Message or armour

For Salomoni, the choice is also a rejection of the stereotype of the fragile feminine princess in favour of a modern, executive image. He says the suit "communicates modernity - that these are women of this century, who do not depend on lavish dresses", and that it signals readiness for a leading role and seriousness, because they represent the state rather than fashion. For Leonor, institutional continuity matters additionally: a shared style with her mother projects family unity.

But the expert does not stop at praise. In his view, excessive consistency starts working against itself - it creates an impression of coldness and distance and erases stylistic variety. "Princess Amalia of the Netherlands, for example, combines suits with dresses that emphasise her youth. Kate Middleton, whom I consider an icon of political communication through fashion, wears elegant and feminine dresses when protocol allows. Leonor, by contrast, comes across as excessively executive and severe," Salomoni says.

His conclusion is that this may be a conscious strategy underlining her future role as head of state - but that there are many moments in which she could risk something different.

What remains unexplained is the more interesting question. How much of this is the choice of the two women, and how much is a frame set for them by advisers? The difference between armour you put on yourself and armour someone dressed you in is enormous, and from the outside it looks identical.