Wow, very, very well done -exactly what a New York summer should look like. For the last few seasons designers have been pushing cotton suits for Summer.
Though cotton suits have a certain appeal they are almost always heavier and warmer to wear in Summer than a high-twist wool like this gentleman is wearing.
I really like the patch pockets on the DB suit - it gives a usually stuffy DB a slightly more sporty, Spring-ish flair.