Tom Hooper’s The Danish Girl is at a double remove: it is based on a novel that draws on real events. The period film features Eddie Redmayne as a woman trapped in a man’s body and Alicia Vikander as his loyal wife who indulges his cross-dressing tendencies, pats his brow, and accompanies him to the doctor. There is much more to the fascinating marriage between Danish artists Einar and Gerda Wegener in 1920s Copenhagen than is depicted in the movie, such as the fact that the trans Einar served as a muse for Gerda’s paintings, and the suggestion that Gerda might have been a lesbian.

The source novel of the same name, by David Bershoff, is about the gradual transformation of Einar Wegener into Lili Elbe through sex reassignment surgery and the evolving dynamics of the equation between Einar and Greta (as Gerda is known in the book). The film moves even further away from the deeply transgressive aspects of the story, casting the marriage in the most conventional terms and using the source material as a platform for Redmayne’s estimable impersonation skills.

The British actor, who won several awards in 2015 for his portrayal of theoretical physicist Stephen Hawking in the biopic The Theory of Everything, puts on another praiseworthy and awards-bait performance as Einar, a soft-bodied and delicate-skinned artist who lets out the woman inside him when he replaces an absent model for one of Greta’s paintings. As he slips on stockings and holds a dress against his body, something stirs inside Einar, and he starts to dress like a woman who goes by the name Lili.

The novel fruitfully explores the ambiguity that marks the introduction of a third person, in a sense, in the marriage. Bershoff writes about Greta, “She felt as if someone were explaining the rules of a new parlor game: she was listening and nodding but actually thinking to herself, I hope I understand this better once the game begins.” Greta encourages Einar to become Lili because it gives her a subject for her paintings, which become increasingly popular. He own transition from awareness to acceptance keeps step with Einar’s transformation.

Hooper’s movie is far too ironed-out to adequately explore the creases and rips of the relationship. The Danish Girl proves that mainstream filmmakers are more receptive than before to tackling tricky subjects such as trans identity and the fluid boundaries between genders, but the movie also sets out the limits of this depiction.

The concept of transvestism is presented in shallow terms, and there is even a suggestion that it initially has aphrodisiacal qualities for Greta, who is intrigued and amazed by Lili. The slipperiness of gender roles and sexuality is as perfectly smoothed out as Paco Delgado’s exquisite clothes. Hooper, who has previously directed The King’s Speech and Les Miserables, is perfectly at home with costume dramas. The attention to couture is perhaps fitting in a movie that charts Einar’s metamorphosis into Lili through the replacement of suits with dresses. But the insistence on beauty and perfection and picture-perfect locations is an end unto itself, rather than adding any depth to a narrative that sorely needs it.

“Not everything is about you,” Greta tells Einar/Lili, but the movie doesn’t give Greta enough of room to explore her psychology. The title is doubled-edged – it is about two Danish girls rather than one – but the movie sticks with one.