You can add an image to a story slide, by clicking the story tool Media objects.
Adding an image to a slide
The following formats are supported: .png, .jpg, .jpeg, and .gif.
For Qlik Sense: You can upload images to the In app folder in the media library. You need to use the Qlik Management Console to upload images to the default folder.
For Qlik Sense Desktop: You can place images in the following folder on your computer: C:\Users\<user>\Documents\Qlik\Sense\Content\Default. Images will be available in the default folder in the media library. When moving an app between installations, the images that you use in the app are saved in the qvf file together with the app. When you open the app in a new location, for example Qlik Sense Cloud, the images will be in the In app folder in the media library for the app.
Managing a Qlik Sense site: Uploading objects to content libraries