(NSFW) What exactly did this horrific scene in Hostel mean?

The scene was where the woman lays in the bath, with the female dangling above her, and then she cuts her and allows the blood to drip all over her naked body?

I only ask because about 16 years ago I had a dream which was quite similar. But it was a goat. I know this sounds disturbing and I probably sound disturbed but I thought my dream was horrific. I have never really shared this dream with anyone else because I was afraid I would freak them out. It must mean something because it was a scene in a movie, meaning someone else understands it? My dream had an erotic overtone to it. Does it mean something in an erotic sense?