1) To add NIP-57 to your Nostr experience (unless you mean something different) you need a client that supports it and a wallet that supports it. Clients: Damus (TestFlight version only at the moment), Amethyst, Snort, Iris support it, maybe more. Wallets: LN.tips, WoS, Strike.army, Vida.page and some others support it. Note that this is for your receiving wallet. Any lightning wallet can pay a zap invoice.

2) The difference is that without NIP-57 a lightning tip is mostly an external thing from nostr. With NIP-57, the tip becomes more integrated with the Nostr experience. With NIP-57, when someone pressed the tip button on one of your posts or your profile, your Nostr client sends a zap request to your receiving wallet. The wallet returns a bolt11 invoice that can be paid by any lightning wallet. Once the invoice is paid the wallet returns a zap note, which is itself a Nostr event (kind 9735, I believe). Since it’s a Nostr event it can be integrated into your client UX. This can be in the form of in-app tip notifications, a tally of all tips sent on a particular post, a list on your profile of who has tipped you, etc.

Basically it turns lightning tips that originate from Nostr clients into Nostr events that can be shown in various ways in client UX.