Earn passive income on your YDF: By staking your YDF or liquidity, you can receive high returns in addition to a "certificate" or "receipt" of your current stake in the form of a NFT. Your NFT holds the keys and all metadata to your current stake, and has all the benefits and properties you're used to with any other NFT.
Your stake NFT holds the YDF & all value inside it: The NFT you receive when you stake holds inside of it all of the YDF and all the value associated with the stake itself. Therefore, when you transfer or sell your NFT on a marketplace, you are effectively selling the YDF principal in the stake and the APR you are earning at.
Fully transferrable, tradable staking NFTs: An important thing to consider is the NFTs you receive when you stake your YDF or liquidity, sYDF or slYDF respectively, can be traded on OpenSea or any other NFT marketplace based on the current and potential future value of your stake based on how much is staked and your APR (depending on your desired lockup period).