For a certain stripe of pop fan, diva worship comes along with having a high tolerance for their unique flavor of psychobabble. So when Anne Hathaway, as the titular singer in David Lowery’s Mother Mary, declares that her new single Spooky Action is about Einstein’s “transubstantiation of feelings”, I ignored the snorts from those in the theater beside me. Finally, I thought, fondly casting my mind back to when Lady Gaga would talk about her music as a reverse Warholian explosion: a pop star who is not afraid to lean into high-concept nonsense. My generosity quickly faded when I began to realize that Mother Mary – the character and the film – was missing a crucial component for any modern pop star worth their salt: self-awareness.

Mother Mary is a one-time music A-lister in search of a comeback after a mysterious event that has taken her out of commission. She seems … haunted, and is experiencing a fashion emergency to boot, unable to find anything to wear for her imminent return to the stage. Three days before she is due to make her big appearance she turns up in the rain at the gothic mansion of fashion designer Sam Anselm (an enjoyably over-the-top Michaela Coel), looking like a rat caught in a monsoon, begging for an outfit that “feels like me”. Sam has moved on considerably since she was Mother Mary’s partner in fashion, and perhaps her lover behind closed doors too. In fact, she entirely loathes the pop star. “You are a carcinogen, you are a tumor,” Sam says in an amusingly ominous voiceover. “The bile is rising.”

Despite all of that, Sam feels a vaguely supernatural pull towards Mary and accepts the challenge of crafting her a new stage costume. In a flurry of fabric and a few snips of scissors, Sam begins working on a look for Mary from the reams of chiffon that she has stashed in a dilapidated barn for such a purpose. Anything goes, says Mary, apart from the color red, for she has been haunted by a demon that has that exact hue. Thus sets the tone for a preposterous yet consistently stylish two hours with some very big acting amid the creaks and wind howls of the barn, extravagant flashbacks to Mary’s high-octane arena shows, a stomach-churning dip into body horror, as well as some truly stunning visual moments that pair Dalí-esque surrealism with the high-tech gloss of the modern pop stage.

The last time Hathaway acted in a musical (2012’s Les Misérables) she came out of it with an Academy Award. I can’t quite see similar honors being bestowed on Lowery’s often incomprehensible style experiment, but she is convincing as a main pop girl in flashback scenes, performing slick choreography with gyrating backup dancers and bathed in blue lights for a serpentine routine to the FKA twigs-penned My Mouth Is Lonely For You. (The soundtrack also features contributions from Charli xcx and Jack Antonoff.) Given that most of the picture focuses on fraught conversations between Mary and Sam in the designer’s “Miss Havisham”-like barn, it seems that a chunk of the film’s reported $20m budget went on creating its arena spectacles. Compared to the pop concert scenes in recent films such as Trap and Smile 2 (both of which get an A for effort in my opinion), Mother Mary’s pop showmanship is in a class of its own.

While Hathaway has the flashier role, the subtler Coel walks away with the picture: her Sam is as distantly glacial and imperious as the Dickensian character she namechecks. Like Mary, she speaks like she swallowed a philosophy textbook, but she gets the best one-liners and finds the pockets of humor in Lowery’s rather dour screenplay. It’s a necessary foil to the overly earnest Hathaway, who plays Mother Mary like it’s Hedda Gabler. To be fair, the clangers in the script don’t give the actor a lot to work with. At one point Sam asks Mary if she “wants to look like a knife”, to which Mary replies: “I want to have a point.” You wonder if Lowery ever found himself asking the same thing.

It’s a relief when the camera turns away from Mary and Sam’s existential debates in the barn to the supporting cast. FKA twigs throws herself into a quasi-erotic tango with Mary in a bizarre flashback involving a Ouija board, while Fleabag’s Sian Clifford has some hilarious reaction shots as Mary’s harried manager. Other popular cast members are sorely underused: Hunter Schafer’s role is superfluous, and Kaia Gerber is barely given a chance to flex the comic timing she impressed with in Bottoms.

Adding to the frustration is the fact that Mother Mary safely side-steps a good deal of the chewier issues that are staring it in the face. For a film billed as a “psychosexual pop thriller”, it has a strange coyness about its central queer relationship that reads as downright prudish in our age of sapphic pop. You might also find yourself wondering about the personal events that led Coel’s Sam, who is described as working class in the film’s production notes but speaks in a regal RP accent, to see fashion as armor fit for Joan of Arc. A smarter film might have even found an intriguing mirroring between Hathaway the movie star and Mother Mary the pop icon, and found space to examine how decades of stardom can wreck havoc on one’s inner psyche.

Lowery’s film can dazzle. But to quote one of the director’s clear references, many will spot his inspirations all too well. A sweeping backstage shot of Mary between performances will clock as a reference to The Cook, the Thief, His Wife & Her Lover to any film undergrad, in an unwise choice for a muddled film that is leagues away from Peter Greenaway’s exquisitely twisted fashion fantasia. And an early scene where reverse shots of the leads’ faces fade into each other is rather too on the nose as a nod to Liv Ullmann and Bibi Andersson in 1966’s Persona. Ingmar Bergman, Lowery is not.

As my screening ended, I overheard a fellow guest describe Mother Mary as a great “gay guy movie”. On paper, it has the makings of one: glamorous actors, a will-they-won’t-they flirtation at its center, and a ghost that seems to be made of shimmering fabric. If only Lowery’s po-faced film had any of the knowingness that could elevate its hodgepodge of ideas into a cult classic. It’s ironic, given that it is a film about a dress.

• Mother Mary is out in US cinemas from 17 April, in the UK on 24 April and Australia on 14 May

• A previous version of this article misstated the budget of Mother Mary; it was around $20m