Something interesting popped out at me when watching Alien. When Ash's face is burning in the flame, it resembled the last engineer to me. The burning of the exterior, how it melted, of Ash's face resembled the Engineer's head in Prometheus that was brought on board with exterior damage and growths which eventually exploded. Has anyone else come to see this?
This is basically a coincidence based on the fact that both the Engineers and human beings (and thus, Ash) have the same body structure. If you take off the facial hair and smooth out the features, practically any face would look like an engineer's face.