Show Summary Notification option not working as expected

[TafThorne]

The Show summary notification option has a description that reads as if it is not selected you will see no notifications on the phone.

However when I have it not selected I see notifications for every single place on both the phone and the Wear device.

This seems incorrect to me. Is that the intended behaviour?

When I select the option:

I am presented with only a single summary notification on the phone.

Which sounds correct.

Perhaps I am reading the description incorrectly and this behaviour is as intended.

I am running a Sony Z3 Compact, model number D5803, Android Version 5.0.2, Build Number 23.1.A.1.28
My Wear device is an LG G Watch.
Wear version 1.1.1.1956917