When dragging and dropping an image (typically .jpg or .png) into the Campaign Manager, the image is resized according to the horizontal dimension (scaled to 320 pixels) and the aspect ratio is maintained. If the resulting image is too large for the vertical dimension, a scroll bar is added. To maintain the best image quality and scale, it is best to start with an image aspect ratio similar to a smart phone screen (~600 pixels high x 320 pixels wide).
