An item that's been repackaged has already existed before and now comes with something new added to it.
You might see companies releasing their old products as "repackaged" editions. This means they took a product, say, an old video game, and put it in a new box or with some extra features, like bonus levels or improved graphics. They're not changing the original game itself, just dressing it up with some new packaging to make it look more exciting. You might also see "repackaged" used for books or movies that are being re-released with some new content added in.
To package again, to give new packaging to.
