“Many magazine photos are actually composite images now”
True. But if you’re going to consider Rockwell’s painting “composite,” you basically have to call almost every painting in history composite, since it is almost never the case that they directly reproduce what they see in any given frame. Rather, they mix observations together, add flourishes, and so on.
Some work from posings, photos, and sketches, whereas some work from the ID. Not all paintings are sourced from modelled studies.
And when you think of a photo, you think of it as a realistic portrayal of some event, captured in time. No one ever took a painting or drawing to be a 100% accurate account.
Photos aren’t good evidence these days.
I often photographed colonial churches in Central America. Once as I was trying to get to a spot that would minimize the telephone/electric lines in front of a church I noticed an artist painted it with all such clutter left out.
It struck me that he could really capture it in the way our memory might filter it and hold it.