The radar chip is especially interesting. I remember being intrigued when it was presented by the ATAP team years ago: https://www.youtube.com/watch?v=0QNiZfSsPc0

The team showed an impressive amount of cool stuff back then, it's nice to see one of these projects shipping on a flagship product. There's more info here on how it's used: https://www.blog.google/products/pixel/new-features-pixel4/

EDIT: found the original presentation: https://www.youtube.com/watch?v=mpbWQbkl8_g . I think the touch sensitive cloth project also made it into a few products.