Leave it up to Zara to reinterpret seasonal trends in the most affordable manner. This summer I got my Jil Sander fix at Zara (since buying the actual Jil Sander would have set me back into a sad state of perpetual brokeness) and, now, I can get my Marc Jacobs’ polka dot fix there too. I absolutely love this blouse with pretty eye-popping dots. The collarless silhouette really updates the otherwise grandma-ish Advanced Style (but also kind of awesome) kind of a thing. 
The only thing: Zara used to do primarily silks, but now they all seem to be blends of silk/acrylic. Oh well, when the price is right….
$59.90 at Zara.
PS. Way back in 2001, I saw Stella Tennant shopping at The Gap on 5th Avenue. She was super dreamy.