The magnetic switch in the video - I have used before, and they do not distinguish between "open" and "closed".
When someone opens the garage door, a notification is sent: "garage door open".
When someone CLOSES the garage door, a notification is sent: "garage door open".
Unless you can provide further explanation, the device only notifies of "activity", not specific activity such as open or closed. In which case, you're being a tad misleading.