His films aren't all the same exactly, but Pablo Larrain has a very distinctive aesthetic that's common to all the films of his that I've seen. Even though this one might remind you narratively of his 2016 character study of Jackie Kennedy in Jackie, it's the lyrical mood he constructs that's even more evocative of his past work.

I'm probably remembering more of them than there actually are, but there seems to be lots of scenes of Princess Diana (Kristen Stewart) wandering through wintry English landscapes, both her and the camera looking out over misty fields and back roads.

I also remember the particular (and peculiar – in a good way) soundscape, where at times the action takes place amid a soft jazz soundtrack, hardly the musical choice you'd expect to depict the ultra-wealthy elite of the UK royal family. Along with the rest of the soundtrack it lends the whole film a lilting, slightly dreamlike quality, as if Diana is barely awake.

And thematically, that might indeed be the case. Her marriage to the stilted Charles (Jack Farthing) is all but over – it's an open secret he's been hanging around with Camilla and she feels physically sick to think she has to spend the Christmas weekend with he and the rest of the family at one of the royal estates out in the country.

Her only consolation is the presence of her beloved boys, William (Jack Nielen) and Harry (Freddie Spry), although she has to share them with the immobile strictures and pomp surrounding the very structured weekend's activities, all of it steered with ruthless efficiency by the slightly fearsome estate manager (Timothy Spall) and the head chef Darren (Sean Harris), the latter actually her friend and confidant.

She's late to every appointed meal or activity, often because she has to go to one of the ornate bathrooms and vomit down the toilet. She has another friend in seamstress Maggie (Sally Hawkins), but she's suddenly removed when it's suspected her presence is making Diana even more rebellious. At every turn and all around her, people's judgmental eyes and the stifling rules and tradition are suffocating her.

Even when she decides to sneak out one night because her own family's property is just over the fence and the house she grew up in is a stone's throw away – albeit boarded up and abandoned – the police stop her during their regular patrols to secure the estate against the paparazzi.

Little of the actual plot asserts itself beyond just depicting a woman already on the verge of a nervous breakdown only crumbling further. It's Stewart's show, and although I didn't need any convincing about what a great actress she is, she's brilliant here.

Capturing the real Diana's slightly Marylin Monroe-esque quality of commanding maturity and coquettish little girl beautifully, she breathes life into Diana not just because she has the voice, stance and look pitch perfect (even down to the slightly breathy way of speaking), she seems to be channelling the stifling claustrophobia Diana no doubt felt at the time, feeling like a beautiful bird locked in a gilded cage, all eyes on her for the next crazy thing she'd do.

Nobody probably has any idea how true to life the decisive climactic moment was, when she finally finds her feet and voice, believes in what she wants, finds her confidence and walks literally onto a battlefield to do what's right by herself and her sons, but it's a neat story turn that captures the escape she was hoping for in triumphant fashion.

Though it's Stewart's movie throughout, there's at least one other standout character. Charles is mostly an uptight buffoon who's so insensitive he doesn't realise – or care – that he got his mistress the exact same Xmas present he got his wife, one the bloodthirsty British press has picked up on.

And Spall as the faultlessly polite and poised but passive-aggressively terrifying estate manager is a little one-note apart from a single scene talking about his military background.

But it's Queen Elizabeth (Stella Gonet) who makes the most impact with the least. When Diana follows her outside one mealtime as she's taking her corgis for a walk – perhaps hoping for forgiveness or release from her predicament through a little bit of understanding – her mother-in-law gives her what might be one of the most incisive bits of advice she's ever heard, and one that makes her realise that she should have known and accepted everything that comes with the life she's chosen.

It's the only few lines Elizabeth speaks in the film, otherwise commanding obedience and fealty to tradition with only her wilting stare, but they bring both Diana and you up short, suspecting she's old and wily enough to know exactly what the younger woman is going through and has simply selected a different path.

There's a fever-dream quality in the cinematography and the design of the film that further mirrors Diana's feeling of muzzy-headed self doubt and fear, appearing on the surface to be beautiful but actually a straitjacket and prison, the perfect blend of form and function.