@AhtishamAshraf Ha, I could not google anything like what you are saying. But found a picture that let me guess the use of this weird button. Let us first look at the picture below.

I think the button on the armature can be called "door closed status button". There is another button B on the magnet bar. When the door closes, Button A pushes Button B, which triggers an alarm or status LED which lights up when door is open.

And as you said, if a buy guy use a screw driver to try to open the door, Button A no longer touches Button B, so sounding the alarm. But if a small bad guy smashes a big hole in the door, and crawl in through the big hole, then alarm won't sound!:)

As per my thoughts it was just to push away because @tlfong01

@AhtishamAshraf Ha, that tiny button with a tiny spring is too weak to push away the huge door! :)

This is to close the door? @t

@AhtishamAshraf Yes, automatically closes the door, and might lock your outside, if you forget to bring the key with you! :)