Rest mode feature allows you to switch Embrace to a higher sensitivity of seizure detection. You can enable Rest mode during the periods of limited movement, for example, when you're having a nap, watching TV, reading a book, or sleeping.
By selecting Rest mode, you'll be activating a more sensitive version of the Embrace seizure detection algorithm. This means that Embrace will be able to pick up mild tonic clonic seizures that otherwise Embrace might not have picked up.
As Embrace is more sensitive to shaking movements when operating in the Rest mode, there's a higher chance of false alarms. This is why you should only activate Rest mode when you aren't physically active.