Named Adaptive alert vibration, you can find it on a Pixel 7a under the Vibration & haptics sub-menu within the Settings app's Sound & vibration menu. Andrpid Police first found evidence of this feature in beta testing back in December, but now it appears to be a fun exclusive for the new cheaper Pixel, at least for the time being.
Going by the feature's description in the Settings app, Adaptive alert vibration sounds like using this feature will only use the phone's full vibration when you're moving or can't see the phone's display. This makes sense, since if the phone's laid face-up on a table or other surface near to you, you're likely to see notifications coming through on-screen anyway.
There appears to be no additional customization beyond toggling the feature on or off. Perhaps we'll see more options in future updates, allowing users to pick their preferred vibration levels from a number of presets.
Bring this to other Pixels, Google!
As Adaptive alert vibration appears only to be a software feature, rather than linked to the phone's hardware, hopefully it'll roll out to other recent Pixel handsets soon. But as we can see above, it's currently not available on other Pixels running Android 13.
Luckily for Pixel owners, one of Google's big selling points is the Feature Drop, a Pixel-specific update package that arrives every quarter to add new, often unique, features. This should hopefully mean you don't have to wait for Android 14 to roll out towards the end of 2023 for smarter vibrations to be an option on your particular handset.
If you're thinking about picking up Google's new a-series phone, then read our Pixel 7a review first. We think it's a fantastic phone for the money thanks to its improved display, cameras and chipset, making it the newest member of our best cheap phones picks. And the adaptive alert vibration feature only makes it better.