Hi,
With open-source software as Joomla and Virtuemart. Everything is possible. Because they are open-source and any kind of coding modification can be applied. But it will require some coding knowledge.
FYI: I like the overall design and menu item organization of sephora.com though. I have already bookmarked it.
Who knows, maybe the next template we release will be partly inspired from their website ;)
By the way; our latest
Joomla Virtuemart Template: Asymmetric has the feature of putting a module inside the main menu drop down. See live demo:
demo.flexiblewebdesign.com/asymmetric/
Implementing this to LightMart will definitely require some custom coding changes, which is beyond our free support.
Alternatively.. you can take an advantage of
using the Custom HTML Module as a menu item feature in the LightMart and build the inside of menu dropdown through the Custom HTML module. That's a possibility. So what will be inside the drop down will be manually coded through Custom HTML Module. (instead of taking the menu items from the "menu manager" automatically) It might be time consuming but eventually it will work.
Regards
Supoirt