As images aren't directly hosted on Print, images must be added through a web url, or directly through a Podio app variable.
Step 1 - Click the Image Icon
Navigate to the "Add Image" icon in the editor menu bar
Step 2 - Edit Image Properties
Add image URL (If you are importing from Podio, simply drag that image variable into your template)
The width and height boxes are in measurements of pixels, adjust these to change your image width and height
Adjust the Horizontal space and Vertical space to your image if needed