Images can be uploaded to articles in slideshows, galleries, next to text, or as standalone images. High resolution images are typically best. If you'd like a standalone image to be the full width of the proposal area, they should be at least 600px wide. "Super" high resolution images are automatically resized to fit as needed. If adding images next to text, you can use the default section styles at the bottom of the content block to set the desired width of the image.