That is indeed a very nice collection of photos.
There are members who are far more knowledgeable about the Neapolitan style pizza than I, but I think that there are several possible explanations for the many variations that you have observed between pizzas made in Italy versus on this forum.
First, as Marco told us a few years ago, at Reply 10 at http://www.pizzamaking.com/forum/index.php/topic,10621.msg94714.html#msg94714
, there were at that time more then 500 pizzeria in Naples City Centre, another 1000 in the immediate province and several more thousands around Campania. With numbers that large, you are going to see a very wide diversity in the ways that the finished pizzas will look. Of the many thousands of Italian pizzerias in Italy, the last time I checked, there were 162 members certified in Italy by the AVPN. I am willing to bet that there are wide variations in the pizzas made by these pizzerias also even when they are supposed to be working off of the same songsheet. I am sure that the same thing happens in the U.S. where chain pizzerias work with essentially identical doughs yet end up with different results. Marco also told us that not all members of the AVPN follow the methods advocated by the AVPN. So, that can affect how the final pizzas look.
Second, with thousands of pizzerias in Italy, they are bound to be using different flours, cheeses, sauces and toppings and different ovens. And different dough preparation and dough management protocols. These factors will all have an influence on the final pizzas and how they look.
Third, the pizzas you showed were made by commercial pizzerias. A few of our members, and most notably Craig with his Acunto oven, have made Neapolitan style pizzas that are perhaps the equal of those made professionally in Naples, but most of our members do not have and use in their homes (or garages) imported Italian ovens dedicated to the Neapolitan style of pizza. Also, our members are largely home pizza makers, not commercial operators turning out hundreds of pizzas a day. With high volumes, there is bound to be variations in the way that the pizzas look not only in the course of a single day but from one day to the next and over the course of a season. As you know, the doughs used in Naples to make Neapolitan pizzas are adjusted seasonally to compensate for the effects of different ambient temperatures throughout the course of the year. These changes are quite likely to lead to even more variations in the finished product.
Fourth, most Neapolitan pizza operators make and use same day doughs for the most part. And they are used throughout the day although it appears that they will occasionally hold dough for later use. Also, with very few exceptions, they are not using natural leavening systems and protracted fermentation times that can exceed a day or more. Many of our members use natural leavening agents and long ambient or controlled fermentations, but no cold storage. These differences will show up in how the finished pizzas look.
No doubt there are other explanations as to why there are so many variations in the Neapolitan style, but these are the ones that immediately came to mind.