But there is so much going on thematically in A.I. that it should be fairly clear that it’s advanced mechas, rather than aliens – because aliens don’t fit.
When they’re outside the church, Gigolo Joe explains “The ones who made us are always looking for the ones who made them.” – So when David and Teddy are discovered by beings who are thrilled to find creatures who lived before the ice age wiped human beings out, and who explain that they feel that human beings are the key to the meaning of life, it shouldn’t be too hard to see the parallel.
I’ve alread said that the robot explanation is the correct onme and makes sense. But I maintain that it’s still not necessarily obvious. Most moviemakers aren’t that consistent. Even Spielberg.