Gorgeous dress! It looks fresh, breezy, and chic. And happy anniversary! Great pics -- so envious that you are getting to enjoy Manhattan. It's been years since I've been there!
That dress looks like the same kind of fabric as my Comrags dress. It is a kind of seersucker, I think, all cotton, very light, and is virtually immune to wrinkles. It is a FABULOUS dress -- like yours, it works casually but can also be dressed up easily with the right accessories. Another wonderful feature -- if you happen to get caught in a rainstorm, it dries of very quickly.
Great purchase! Enjoy the rest of your time.