What Theme are you using? I guess DeviceDefault . You could change to Classic Theme and get a different result. Why? Because the Notifier, when loaded on an Android device uses Google's way of displaying the pop-up and the actual display varies based on the version of Android you are using the app with. You cannot change the way the Buttons display with Blocks when you use a DeviceDefault setting.
This is what you can control with the Notifier