Use this tool to create image sliders. Like this, or this one. You need URLS to the images you want to use. The easiest way to do this, is to upload the images to the Grid, and then drag the crops into this tool. For every image we need a small version for mobile - this should be around, but not less than 480px wide. For desktop the recommended size is 780px for normal articles, and 1300px for immersive articles.