Yeah, this is one of my (very few) complaints about NMWA. They will carry pics on their website to highlight a brand, but won't actually carry the product depicted in the photo. For instance, I really liked the Camoshita blazer with the sharp looking Asian dude. While NMWA did carry a blazer similar to that one the pattern was much tighter than the one from the photo. Liked the blazer in the photo, didn't care too much for the one carried in stock.
In the case or Camoshita, the featured Asian man is Kamoshita-san himself. He is a style icon in his own right as well as the brand's designer and creator, so the picture is relevant to the brand. In general for the pictures on the brand pages, changing them every season to reflect what's in stock would be an additional headache, and they're intended to be photos that give an idea of the brand's heritage and story as opposed to advertising specific products. But when we post lookbook photos on tumblr, they almost always feature something we are carrying.
Anyway, I definitely understand it's frustrating to see something that looks great and then not be able to purchase it from the store, but it's just a matter of balancing the ability to showcase the brand permanently and sell their products seasonally.