Quick answer: With Secret Gifts, your community can buy items straight from your wishlist, but the specific item and its value stay hidden from you until it arrives, unless you choose to reveal it early.
How it works
You'll get notified that a gift is on the way, and the gifter's name if they included it, but the item itself stays hidden. Your email confirmation won't show the item name or image either.
Turning it on
Go to your settings page, open the Wishlist tab, and toggle on Secret Gift Mode. This applies to all your gifts, there's no way to make only some of them secret.
Revealing early
Open the order on your Orders dashboard and select "Reveal" if you'd like to know what it is before it arrives.
Not the same as Surprise Gifts
Secret Gifts hide items you already picked. Surprise Gifts let fans pick from categories you set, so you don't choose the specific item at all. See "How do Surprise Gifts work?"