I think the scene was intended to be a rape scene, maybe a statement on objectification and how our own desires define what we consider to be an 'object' when it suits us. I could, of course, be reading too much subtext into the situation, it's one of the weird things about Ridley Scotts' work is that he can go from generic blockbuster stuff like Gladiator to deep introspective human-condition stuff like Blade Runner and Prometheus, I suppose it depends on what he is given to work with in the first place.
The story would have been better presented as a mini-series I think, but in the early 80's such things were pretty much unheard of, it was either a 'standard' TV series or a one-off movie.