Design of the screen not displaying correctly

Hello guys,

I am currently trying to design my app and I don’t understand how it works.

I would like a screen like that :
Screen 1

But when I do the preview it is shown like this :

Does someone has a tip for me ?
For information, the white thing is just a regular “simple” rectangle.

Thanks for your help !

Welcome to the community @Tom2
The rectangle will hold its height property regardless of the device used. So if you build the screen with a rectangle that is 400px and the device has a screen height of 667, the rectangle will remain 400px. Now if you’re on a slightly larger device where the viewport is like 812px, then the rectangle will still be only 400px, making the rectangle appear smaller on larger devices.