#636: Responsive breakpoint switcher - added condition if mobile image data exists

Author: yolouiese

app/code/Magento/PageBuilder/view/adminhtml/web/js/content-type/image/preview.js

@@ -93,6 +93,6 @@ export default class Preview extends BasePreview {
     public getViewportImageData() {
         const desktopImageData = this.data.desktop_image;
         const mobileImageData = this.data.mobile_image;
-        return this.viewport() === "mobile" ? mobileImageData : desktopImageData
+        return this.viewport() === "mobile" && typeof mobileImageData !== "undefined" ? mobileImageData : desktopImageData
     }
 }