I can't see the art you're referring to, I need some 'plug in' that doesn't want to 'plug in'.
I have seen some of this stuff in the past and I think it probably was inspired by what they saw in the sky.
The Madonna and child with the guy looking at the UFO in the background and the one with the flying disk shining a beam of yellow light down onto a window or door (I can't remember which) require too much imagination for the time, I think anyway, people were still getting around on horses or horse and cart combinations.
For them to include flying disks in the art of the time, I think they were very impressed by something they actually saw in the sky.
Sorry Pragmatist, I forgot Youtube doesn't work sometimes outside of the U.S.
This is a small collection from the video. A great deal of these carved items are not seen by the public.
When scientists generally discover weird artifacts that don't fit with what is already known, items like these get put on the shelf and are ignored. Perhaps they refuse to believe in aliens coming here. However many ancient tribes speak of the aliens returning to Earth on a later date. I suppose when these aliens show up, we'll see for ourselves what these ancient people around the world were talking about.
I think the problem is with my computer, I resurrected an old heap of a laptop and put the free Ubuntu oprerating system on it, it's me being a skinflint, it doesn't work very well, I'll upgrade it soon.
Very interesting pictures, the central vertical peice is really quite remarkable.
Google 'UFO's in ancient art', there are quite a few interesting paintings out there.
Apparently there are mentions in the Bible of "flaming wheels' in the sky, I'll have to talk to one of the guys at work that has in interest in going to Church etc to ask if he can tell me which section of the Bible I should look at. It would be good to read of the flaming wheels in the sky in context.