Mega Menus work very well for ecommerce stores
Ecommerce stores typically have a fairly large site structure (lots of categories and sub-categories).
Show the sub-categories as columns – ideally 3 to 5 – if these sub-categories have sub-sub categories.
Optionally show an image for each column.
If you only have a few sub-categories and no sub-sub categories, then you can have a thumbnail for each, like below. Or these can be the featured sub-categories, followed by the rest as text links.
If your store has a very big navigation structure (lots of menu items), you can have a “multi-dimensional” Mega Menu that lets users dive into a few levels of menu items.