The application view within Designer shows an outline of the structure of your application. From this view you can add new screens, layers, and controls to your application and expand it to include the visual structure and organization appropriate for your product.
Storyboard uses industry standard formats for assets, such as images and fonts, as much as possible. When a project is created it is automatically populated with an images and fonts directory. To import new images or fonts to use in your project, you can simply copy files with supported formats (png, jpg, bmp, tga, ttf, otf) into these directories. The assets are available for use within your project to set as a property on a render extension or by dragging and dropping into a particular screen canvas directly.