Picture a kind of Joomla classifieds website, with ads displayed in a grid layout.
Ad images will be displayed via link (html code in JCE editor), not through an image application.
The images need to be displayed as height 300px, width 250 px no matter if portrait or landscape (landscape can be cropped to fit this size). The images need to shrink/be responsive if viewed on a mobile phone or smaller screen size.
The ad container itself is responsive.