Google teases mysterious October 4th launch with more mysterious rectangles

Google is holding an event on October 4th where it's widely expected to unveil its latest smartphones. Somewhat unusually for the company, it's also engaging in a bit of guerilla marketing — we've seen more than one building-sized advert trailing the event, as well as pictures of a statue in Brooklyn Bridge Park shared by Redditor dolan313.
Both adverts and statue look just like the original video teaser released by Google this week, showing a plain white rounded rectangle alongside t