In your Profile, your Loves is a list of items you love and have saved from anywhere (double tap in app, from safari on your phone, from desktop using the Chrome extension)
It's a quick place to save all of the things you love in life. These could be things you want to buy yourself, or things you want others to purchase for you as a gift.
The "Lists" feature was created to help you organize your Loves. This can be for a specific event (baby shower, birthday, christmas, etc), for a specific person (children's lists, spouse, family members, etc.) or for a specific category (home, shoes, accessories, etc).
You can also use your Loves and Lists as a catalogue of things you already have by tagging items as 'Owned'.
Other users can mark items on your Loves/Lists as 'Purchased' once they've purchased them for you, but to keep some surprise in your life, the app doesn't immediately show you this by default.