Before trying Siri Recap or Live Rewind, check the devices on your wrist and in your pocket. 9to5Mac's watchOS 27.3 beta walkthrough shows both recall features on an Apple Watch Ultra 4 and their opt-in controls. Apple's support guide lists Apple Watch Series 12 or Ultra 4 paired with an iPhone 16 or later, excluding the 16e, as the supported combination.
Recap turns conversations into summaries in the Siri app. It can be enabled only at chosen times or locations, and Apple says summaries expire after up to seven days unless saved. Live Rewind is a shorter look back at speech from the last 15 seconds, invoked with a double press of the Digital Crown. The watch gives an audible and visible signal when it listens, so someone nearby can tell what's happening.
One keeps a brief written memory. The other helps with a sentence you just missed.
The beta also includes a Fitness+ Gym Strength change, but recall is the reason to watch this walkthrough. Apple calls Audio Intelligence a beta feature. For many iPhoners, the availability rules may matter more than the demo; I'd set a narrow Recap schedule first and decide whether its summaries earn a place in everyday use.