This looks really polished... why didnt Sony show this at E3 too?
Good question, I dont know. Many PS4-titles were shown before and after the conference. Maybe because the focus should be on the four AAA titles: Ghost of Tsushima, The Last of Us 2, Death Stranding and Spiderman.
Games with so much effort have high development costs and make a lot of work. As a company, you have to make sure that these games sell enough and get attention. But personally, I would have shown all the other new ps4-games in the conference as well too. Or Sony has the motto: "The E3 is a big show and you will experience new games from beginning to end, not only at the conference." Quite possible.