This is Ektachrome 100 Plus (EPP), a '90s film used extensively by professionals while kodachrome was still available and development was available, etc.
Look how the slopes match more closely compared to above (except in the deep shadows). And this isn't even the best Ektachrome film, there were even better subsequent films.
For example a very good film for portraits: Astia 100.
Color rendition is very good indeed. And this was an extremely fine grained film.
The rest, as they say, is history.