Getting permission for Push Notifications
You should see a pop-up asking for your permission to send push notifications to you. If you provide permission, you will also see a demo message.
You will not see a permission box if you have aleady subscribed.

In case you missed the demo pop-up box, here are some screen-shots of how it looks:

Confirmation Message
Here's how the confirmation message looks

Push Message
Here's how a push message looks