Inserting images into a table or dynamically changing images in a text box are not not current capabilities of Qlik Sense. So you cannot do this through the standard UI. We are working on making improvements so you could do things like this.
There are two options open to you. You could create a web mashup and have the images appear through a standard webpage with Qlik Sense charts on it. Or you could use QlikView (in QlikView you can put images in a chart or dynamically change the image in a textbox).