Ridley Scott intentionally made his alien surreal and ambiguous. We don't know what it did when we weren't looking at it, and neither does Scott for that matter. Those of you who see Lambert's foot without a shoe and think bare skin must mean that she was LITERALLY raped don't have very good imaginations. What the hell happened? We'll never know. She was swinging off the ground and obviously died some savage death that we never see or really understand. That's what makes it SCARY.
Not until Aliens was any kind of real logic applied to the creature. Until then it was Scott's vision on the screen. Moisture on the eggs drips upward instead of down. You can explain that however you want with the fan fiction that is the Anchorpoint Essays (and don't tell me it's anything but fan fiction created in order to fill in the huge gaps and breaks in the films that the film makers themselves left) to but the fact of the matter is that IT SIMPLY LOOKED GREAT! Scott didn't sit down and invent some kind of device in the derelict that justified the upward-dripping liquid, he simply provided a wonderfully surreal, ALIEN looking image. In my opinion, his alien is the most ALIEN of any of the others in the sequels because he provides us with so much mystery.
I can't think of one Alien sequel that didn't break the ideas put on screen in the film before it.
However, I can't stress enough that I hate the new idea. Seeing movie monsters go through all kinds of dumb and extremely fast adaptation and evolution is the oldest, cheapest trick in the creature movie book and the fact that the majority of the people here are all about this new idea really makes me feel as though there is truly NO HOPE for the series to get back on track. The fan base ITSELF would rather ooh and ahh at whatever new alien incarnation we can throw on the screen than allow what was already established in the series take place with new interesting characters and a unique plot. Alien is becoming the same camp that most great horror franchises turn out to be. I wish that Alien wasn't turning into direct-to-Sci-Fi-Channel movies transformed into big screen films, but I guess that's how it has to be. It's just sad that the fans themselves are so eager to see it happen.
The fact that every intelligent post I have read here is surrounded by half a dozen posts repeating the same ideas and defenses that were revealed to not be feasible says a lot. I feel like we need a FAQ for this so people can read it and not feel compelled to post "But we have never seen a young queen before!" or "but we've never seen a predalien before!" on literally every page in this thread.