In case, you haven’t realized there is a very subtle change in notifications on the Apple Watch depending on whether you have the Watch version of the app installed on your Apple Watch or not.
As Mac Kung Fu points out, the Apple Watch notification has a round icon if you have an app installed on your Apple Watch for that notification, so you can tap on it to launch the app and take action.
The Apple Watch notification has a square icon if you don’t have an app installed on your Apple Watch for that Notification.
As you can see the screenshot of the Notifications for the Due app (iTunes link) below. The Notification with the square icon is when I didn’t install the Watch app for Due on my Apple Watch.
The Apple Watch notification with the round icon is when I installed Watch app for Due on my Apple Watch.
You get the same number of options for both types of Apple Watch notifications. I can mark the task as done, ask Due to remind me about it after one hour, or simply dismiss the Notification.
The only difference is that, when the Apple Watch notification is round I can either tap on the Due icon to launch the Due app on my Apple Watch or tap on the text part of the Notification to open the reminder, which launches the Due app and gives me a few more options such as reschedule the reminder, set auto snooze or delete the reminder.
Mac Kung Fu has also discovered why Mail notifications are sometimes square, and sometimes round:
If the notification is square then the message is not in your inbox – or not in the mailbox that you configured in the iPhone’s Watch app for notifications. All you’ll be able to do is dismiss this notification. If the notification is round then, yes, it’s in the inbox or designated mailbox. You’ll be able to reply to it from the notification, and flag it, and so on.
Had you noticed this subtle difference in the Apple Watch notification? I’ve been using the Apple Watch ever since it was launched in May.