Indeed what you are seeing is not what I mean. You must be getting some sort of advert for first time users.
This is what the page looks like below. You'll notice that some products (those with variants) have a button named "Quickshop".
Clicking on that button, spawns a modal window with the product view in it. It is basically no different than navigating to the page in question, but it gives the customer the impression that they are not leaving the browsing page and that they can buy the product with fewer page loads.
Here is what it looks like:
Essentially, in Hikashop we have products that can be purchased directly from the category view. Those that have variants like "size", "Color" etc. Have a button that says "Choose Options".
In the JCrew example, instead of "Choose Options" it displays the wording "Quickshop" and when clicked it opens a modal window with the product view in it.
I don't think this would be too hard to do, but I wanted it to run it by you guys first in case there are resources I can leverage already built in.