Using a mobilescreen as a modal

I have a mobilescreen, and it contains a handlful of controls, the uppermost is a mobileimageviewer, but that doesnt seem important.

If I show the screen using showmodal, no matter what presentation style I choose, I get a wide bar along the top that looks like the background to “large title”.

The uppermost controls, whatever they are, appear under this bar.

I can find no property to remove that.

Is there one? Or something I can call in the Opening event?