CZML image not load on Cesium.Viewer

CesiumJS
1

Thanks to cesium team for providing such a great tool.

I have kmz that containt raster image from aerial photo.
I convert my kmz to czml using cesium converter (.net) and I load the result to cesium viewer.
It works, but to show the image I have to click the rectangle and the image show up.
How can I show the image without clicking ?
Here is my code :

var viewer = new Cesium.Viewer(‘cesiumContainer’, {
                imageryProvider: new Cesium.OpenStreetMapImageryProvider({
                    url: ‘http://tile.openstreetmap.org/’
                }),
                baseLayerPicker: false,
            });
            viewer.dataSources.removeAll();

            viewer.extend(Cesium.viewerDynamicObjectMixin);
            var czmlDataSource = new Cesium.CzmlDataSource();
           czmlDataSource.loadUrl('/Czml/SpatialAnalystMelak.czml');
            viewer.dataSources.add(czmlDataSource);
            var destination = Cesium.Cartographic.fromDegrees(115.810681, -0.397550, 35000.0);
            var flight = Cesium.CameraFlightPath.createAnimationCartographic(viewer.scene, {
                destination: destination
            });
            viewer.scene.animations.add(flight);

What is wrong on my code?