'I KNOW not all the girls enjoy it," writes one punter, of a woman he has paid for sex with, "but I'm not paying them to enjoy it - just to pretend that they are." This comment, one of many incorporated into two artworks in the Unmasked exhibition at GoMA, Glasgow, comes from a website called punternet on which clients review prostitutes almost as if they were hotels on TripAdvisor.

There are many others like it: reviews that criticise women for appearing tired and miserable, for being too pregnant, for refusing to provide certain services because they say they hurt, for not faking enough enthusiasm. If ever there was a show to demonstrate just how much women are objectified and degraded in the sex industry it is this one, with its litany of fantasy, expectation and misery.

When I first came across punternet while researching an article on saunas and escort agencies, I was shocked by the very existence of a consumer website where women were rated, their services described, bodies judged and performances appraised. I don't know why I was so surprised. After all, it seems inevitable that a site like this should exist in a virtual realm that contains revenge porn, dating apps and reviews of almost everything, as well as prostitution. But punternet belongs to a mostly hidden world, one which many of us close our eyes to. We don't try to find it and we don't want to know about it.

Loading article content

Unmasked has already attracted controversy. Sex-worker activist groups have objected, with rights charity ScotPep saying that it is "offensive and dehumanising". A spokesperson accused the exhibition of being "feminist propaganda" designed to push for the criminalisation of the sex trade - a move which it rightly says would make sex workers less safe.

But it is not the exhibition that is offensive and dehumanising, but rather its content. Unmasked features two separate artworks: Invisible Men, which reproduces some of the punternet reviews and Memoirs, which "reformats" the comments in more abstract form within a book. They feature reviews which rate experiences as like having sex "with an attractive sack of spuds" or "a door or piece of furniture" or "an African shop dummy". Another compares a woman to a horse that "should be put out to field or made into glue".

I don't pretend that punternet reflects all punters - nor are these reviews typical of all on the site. The Invisible Men Project is a selective edit, and one with an eye for the miserable or shocking detail. But the depressing fact that there are some entries like this should be enough to remind us that the "happy hooker" has always been very nearly a myth. There may be a few sex workers who get great job satisfaction, but there are enough who really don't to make us pay attention.

And it says something that two artists, working entirely separately, have come up with two different works both looking at the same site. I can see why. These punternet reviews are the part of the story that is often missed in journalistic accounts of the politics and workings of the sex industry. We live in an era in which we are assailed by tales of sex workers, often presented as tragic victims or strident activists; the former speaking of violent horrors, the latter saying they chose this work and want proper rights. But in these artworks is the story we don't often get - the view from the user. It sheds another light on why the sex industry exists, how it works, and the sufferings of some women within it.

For instance, again and again in The Invisible Men Project there are comments like these: "Her heart doesn't seem to be in this job." "She's doing it under sufferance to earn money, and gives a pleasant time but there's not much real warmth to the show." "This poor girl needs a break, a new profession and possibly an operation." And these aren't notes of compassion: for the most part they are complaints, gripes about the failure to perform to produce the full, enthusiastic "GFE" (ie, Girlfriend Experience).

It is not difficult to see why sex-worker activists are objecting to this exhibition. As part of GoMA's social justice programme, curated by the Glasgow Violence Against Women project, it does indeed have propaganda exhibited alongside it - it aims to change attitudes, to drive us closer towards criminalising the purchase of sex. For me, that is disappointing and limiting - since I am not convinced this is the answer, and do fear for those women who would continue to be at risk, possibly a greater one.

But, whatever the attached propaganda, these potent artworks tell a story we should listen to. They also indicate that the problem is not so much in the act of buying or selling a body - which, theoretically, in a gender-equal world, could be done as a simple exchange and matter of choice between two people - but in our wider culture. It is there in a society that creates certain expectations not just of women, but of men who are drilled, from youth, to think of women a particular way. And the use of prostitutes is only one manifestation of this.