Auto Size Feature for Large Images
If you are using the Dallas Template, there is an Auto Size Feature for large images that fill the width of the content page.
When you insert your image - select Auto Size as the Class. This will auto-size the image on the content page to fill the width of the content page and it will properly resize this image when the content page is viewed on a mobile device.
*Please Note: This is only for large images that you want to fill the screen. All other images should be sized to less than approx. 400px within a content page.