Can you explain "Push notification frequency" Doorbell setting better?

[user_768990797754519_768990797754519]

What does the push notification frequency setting actually do? ie. What does it mean when it is set to 20 seconds (the default)? I can't guess it. For further context, I am wondering if it is that it sends a notification every 'setting value' seconds (eg. 20) while a notification event is happening? Is it doing a check-in every 20 seconds when nothing is happening? (would that cause extra network or power usage in the phone for normal non-notification times if I change it to a shorter time?)