This is one of those weird cases where the movie gets everything wrong while getting some things strangely right. While Bram Stoker's Dracula was set in 1893 and predates all of this film nonsense, Bram Stoker's Dracula is set in 1897-- for the express purpose of this scene according to Paul Foster's essay in Textual Revisions: Reading Literature and Film. Here's the scene in question.
To answer part of the question, were there erotic films of this nature in 1897?? Our first reaction might be to dismiss the idea that the characters were in a porno theater before 1900 out of hand, but it would be wrong to accuse the directors of getting something that wrong--I'm sure they took lots of film history classes in college too. So what erotic films could they have been watching in 1897? Well the first one to come to mind is Le Coucher de la Mariée, whicg came out in 1896. You can watch all 90 seconds of here. By our standards its pretty SFW and probably wouldn't even warrant a PG rating today. The original version was estimated to run about 7 minutes, but we don't have the rest of the film--only the most erotically charged parts got saved (I wonder why..). Another posssibility might have been Après le bal le tub from 1897 (see it here -- semi-NSFW, but still YouTube ok) which might have possibly maybe been in circulation to Bohemia in the same year. Not likely, but I'm stretching it for Coppola's sake.
BUT these weren't really pornographic films in that sense--they were vaguely erotic and probably wouldn't have stirred up that much controversy--the first one was played at the 1900 Paris Exposition Universelle and didn't cause any particular riots--although the 18 second May-Irwin Kiss (1896) nearlt caused every newspaper in the United States to riot. Indeed, the first surviving ‘hardcore’ pornographic film doesn't arrive until 1908, from France: A Les Culs d’Or (At the Golden Bottom). As Dave Thompson explains, the film
Dissolves to a view of a country inn, its white plaster walls weather-beaten and stained. A portly, middle-aged and waxed-mustachioed musketeer, clad in all the finery one would expect rom that noble profession, stands outside, knocking on the door and hammering on an outdoor table. He has traveled far and is in need of sustenance.
The innkeeper, however, has no food. But, unwilling to disappoint so distinguished a customer, he instead ushers the visitor to a seat, then hastens to where one of his staff, a pretty, plump young girl, is cleaning glasses. They exchange some words, then she approaches their guest, leads him to another table, far more secluded than the first, pours him a drink and informs him what is really on the menu—herself.
With every scene ushered in by one more in a dizziying panopoly of excruciating puns, each allaying some form of physical intimatcy with a food stuff, the cavalier samples each ‘dish’ in turn: the seafood la crevette, as he extracts one finger from between her legs and tastes it; asperges en branches (an asparagus dish) as he removes his own pants; saucisse (sausage), moule (mussel), the chicken and mushroom hors d’oeuvre bouchees a le reine; and so on, until the cavalier’s climax marks the end of the first course, and the innkeeper serves up the dessert, a second naked girl, cross-legged on a serving platter. The trio fall upon one another with gusto, sandwich a la gousse, and there the reel—and the film—concludes.
Unfortunately, I could not find a copy of this online, which is a great shame. However, the first American pornographic film A Free Ride (1915, is available on wikipedia [SUPER NSFW]).
So the answer is yes there were erotic shorts available at the time the movie was set, but no they werent any of the ones displayed in the background of the 1992 film. Instead, the array of films in the background seem to be cuts from early erotic shorts, and various scenes from Melies' early horror films like The Devil's Castle. and a completely unrelated cut of Lumiere's Arrival of the Train at the Station. So this keys us into one of the glaring factual errors--it is unlikely that this weird pastiche of scenes would have been played at any theater in the history of film.
However, one thing that the film gets accidentally(?) right. Eastern Europe, for whatever reason very enthusiastically embraced film technology, and they were one of the first areas to begin showing and producing film. Bohemia and Prague were especially known for their embrace of film and their showings of erotic films-- Erotikon and Extasy in the early 1900's were two of the most controversial and erotically charged movies of the century--the latter shows nude swimming, intercourse, and is believed to be the first "capture" of the female orgasm for a movie. But (and of course there's a but) it would not have been common or very accepted to bring a woman into these sorts of theaters. These were very obviously male-dominated spaced--they were called stag films for a reason-- and while prostitutes were sometimes brought to these events, is unlikely that Mina or Lucy would have been welcome or accepted in this men's space.
Username checks out.
Out of curiosity u/annalspornographie how did you get into this particular field of study?