Yes, depending on the mod, of course. Mods change the image files. They can make many changes, but in some cases they are limited as they only affect images, not text or the basic way the game works. For instance, a particular item (or set of items) of furniture could be changed to look very different, but they will still appear in the store under the old label. As I said, take a look through the posts in the VF2 mods forum. Each post shows a picture of the mod, often in situation in the game.