ESL applications have control over how ESL objects will appear across different resolutions. You have the option of keeping your ESL objects the same size, independent of the resolution it is being run on (screen size X Y), or having your ESL objects scale to the resolution the application is being run on (device units or dialog units).

You do not have control over how your dialog objects will appear on different resolutions. That is totally dependent on the screen resolution.

To keep your ESL objects and your dialog objects the same size proportionately across resolutions, use a screen size of dialog units.