Dummy image in the Neos backend


i have a NodeType with an ImageEditor.
When i unselect an image in the Neos backend, there appears a dummy image in the frontend preview of the backend.
In the normal frontend of the page is no dummy image.

Why does appear a dummy image in the backend, when there is no image selected.
And how can i reach that no dummy image is displayed.

My fusion-template looks something likes this:

prototype(Test.Site:Content.Hero) < prototype(Neos.Neos:ContentComponent) {
    src = Test.Site:Component.ImageUri {
        @context.asset = ${q(node).property('image')}

    renderer = afx`
        <div id="hero">
            <section class={props.src ? 'hero' : 'hero no-hero-image'} style={props.src ? 'background-image: url(' + props.src + ');': null}>

The code works fine in the frontend but not in the preview of the backend.