Maybe I'm missing the point but why is this an achievement? I've seen Google images do this for years (from the backend, sends the users viewport dimensions and then automatically calculates the optimum filling). For years (Warning NSFW!) vusker.com has been doing this client-side in their thumbnail and gallery view. Plus look at the vertically stacked posts from Pinterest.

It seems more a marketing ploy to get attention to the great service chromatic.io is providing?