I tried to have the same menu as: http://www.kriesi.at/themes/abundance/ when your click on shop.
I do this:
1. Create your Shop Menu item
2. Tick Use as Mega Menu
3. Add a custom link leave label blank, in the URL just put '#'. Press add to Menu
4. Slot it under the shop Mega Menu, leave "This column should start a new row" box unticked
5. In the title place this code in and replace the URLS.
6. Add as many images like that as you wish going on to new rows as you need to.
but could you give me the size of the image and how can do two menu?
thank for your answer.