Help with layout

Hi!
This may be a very basic question, but I still need some help

I have been asked to help try and fix this website (link below) for a small shop who I do work for.

What needs to be fixed is the image bar bellow the menu with the "A/W collection" wirtten on it.

The image does not move fluidly with the rest of the layout when the browser is resized.

Any help would be greatly appreciated.

http://www.rarasuperstar.com/