According to the Verge, the paid replays allow the users to purchase replays at a cost of $0.99 for every three messages.
Earlier, every photo or video message that was sent to the users directly from other users disappeared forever after they had viewed it, but a few years ago Snapchat started allowing the users to replay one already-viewed message per day.
The users will be able to use that replay on any message that is received by the users, but it is still one-time only. The users will not be able to pay to watch the same photo or video again and again.
In addition, the new Lenses feature allows the users will be able to press and hold on their face to activate a panel when they are lining up their selfie, where they can pick different Lenses. Each one will have unique instructions. It appears that some are interactive, like tracking their face and changing when they move their eyebrows or mouth and new ones will appear each day.
The company also promises other features in a blog post about the update, including an achievement mode called Trophies.