It could also be argued (with the benefit of seeing Aliens) that the drone was in the process of becoming a warrior in the narcissus; just like it's metamorphosis from chestburster to adult, warrior could be considered the next stage of metamorphosis (where the creature loses its protective dome/head shell left over from its larval stage after a day or so or being an adult) - I've often imagined that had the runner survived a little longer in Alien 3, it may have appeared more like the level guardians in the Alien 3 video games 😊
Edit: Should also note that on that topic, I feel that all of the creatures at Hadley's Hope would have originally looked more like the big chap prior to Ripley and Co. Arriving on the Sulaco.