I'm more interested in what was going on before the visit, because the myth is that Jobs was like Prometheus. To counter that myth, we must look into what people knew earlier. Quoting from the Standford link I mentioned before, at
http://web.stanford.edu/dept/SUL/sites/mac/parc.html :
> Both the Macintosh and Lisa projects were underway before the 1979 visit. Documents in The Book of Macintosh (a collection of essays, technical specs, and brainstorms written by Jef Raskin on and others) dating from the fall of 1979-- months before the PARC visit-- show that the Macintosh was going to feature user-friendly interfaces; a screen that could handle multiple fonts (that is, bitmapped screens); graphics capabilities; and a graphical input device
It also comments that the myth "assumes that Xerox PARC's ideas weren't well-known before Apple engineers saw them, or had even been actively kept hidden from public view." I see echos of that in your own comment that Smalltalk was a secret. As that Stanford link points out "Bill Atkinson had read about Smalltalk as an undergraduate. Some had worked at PARC: Jef Raskin spent time there during a sabbatical year at Stanford, and had a number of friends who were researchers there."
I think you have misremembered the part about Smalltalk and overlapping windows being a secret? Ingalls wrote "The Smalltalk-76 programming system design and implementation" for POPL '78, in Proceedings of the 5th ACM SIGACT-SIGPLAN symposium on Principles of programming languages (doi:10.1145/512760.512762). It shows overlapping windows for figures 1-3, where figure 1 is "A typical Smalltalk display." It also has "if the stylus is depressed within the window, the content is
redisplayed, thus showing it “in front of” the other windows", which is a description of how overlapping windows works.
As some additional background, you mentioned "forced by management to show Steve Jobs all the secret stuff". This is because, and quoting again from that Stanford link, "Xerox's venture capital arm had recently made an investment in Apple, and had agreed to show Apple what was going on in its lab."
A lab, by the way, which received thousands of visitors each year.