For example, to learn the size of the current media (e.g., the window containing your app), you can use MediaQuery.sizeOf: MediaQuery.sizeOf(context).
Querying the current media using specific methods (for example, MediaQuery.sizeOf and MediaQuery.paddingOf) will cause your widget to rebuild automatically whenever the property you query changes.
On the other hand, querying using MediaQuery.of will cause your widget to rebuild automatically whenever any field of the MediaQueryData changes (e.g., if the user rotates their device). Therefore, if you are only concerned with one or a few fields of MediaQueryData, prefer using the specific methods (for example: MediaQuery.sizeOf and MediaQuery.paddingOf).
the MediaQuery docs say https://api.flutter.dev/flutter/widgets/MediaQuery-class.html