This film is trying to be a dark version of a David Hamilton film, but it only succeeds in being capricious and illogical. The two girls who are meant to be the center of the story are treated by the filmmakers as marionettes. Are they supposed to have the obsessive/reluctant lesbian relationship we saw in Lost and Delirious? Are they supposed to be a devoted pair against the evils of the world? Are they supposed to be only having the innocent girl/girl affections of Un été à Saint-Tropez? Apparently, all of these at the same time. Really, they just do whatever the script says for no good reason, and this is an insult to them and their secondary players who are not bad actors. Jacqueline Bisset, who plays the headmistress, is likewise misplaced and clearly is acting above the level of writing she's given.
As said elsewhere, the film is all over the place; tender one minute, gruesomely callous the next, with an ending that is pedantic in its melodrama. The title is about some other film, since this one presupposes to be about girls who are either to be sold to nobles as pretty sex toys or coldly buried in the basement. Yet there's no hint of training in the "Art of Love", either in the `70s sense of The Story of 'O' or even a softer version. Sure, there's discipline and dark secrets, but neither come from an institutionalization of sexual slavery to men. The "prima ballerina" is simply given over to the prince after having trained heavily for a dance performance. Here, Hidalla suddenly and inexplicably begins openly flirting with the prince, which leads to equally sudden and unfounded tragedy for Irene. And the simple fact that the best girls are meant to be given to nobles doesn't justify all the secrecy and macabre attitudes among the girls and staff of the school; this was a regularly understood practice worldwide throughout history, of which the misogynistic culture remains, if not the institutions. Why would this need to be kept secret from anyone, either the girls or the neighboring townspeople? It would more likely be the accepted way of things as touted by the nobility, with parents (rich or poor) happily handing their girls over for the chance to be married into money and the girls quite possibly fighting tooth and nail to better their peers in the effort. It just doesn't ring true.
Finally, the headmistress is shown alternately allowing and even causing the deaths of her girls (but to hide what, really, the records that show the girls to be commoners?) then standing up for one against a too-affectionate staff member. And this to hide her own past ephebophilia? Very little of this film makes much sense. Even the "under the waterfall" sequence, which promised a David Hamilton-esque interlude, ultimately led nowhere as a side-plot that proved nothing that could not have been mentioned in passing.
If you're looking for pretty, nubile, nude girls, try Hamilton (and no, underage nudity is not prohibited in most countries if it's not considered inherently sexual, but I suspect the "prima ballerina choice" scene here was done with body doubles). If you're looking for strong young females who are fighting for their lives, look in a dozen other places. This is only good for a few, short moments of earnest concern and affection between two girls that are injected randomly into a film primarily about shame.