Image Module - Eonic/ProteanCMS GitHub Wiki
The only non-standard field here is 'Image'.
To add an image click on pick (or Edit Image if you have previously selected one) which will pop-up an image picker where you can go through all files added via the resource library and simply select the image you want to use.
Once you have selected the appropriate image you can change some of the images properties. The size of the image is automatically retrieved and it is recommended to resize the actual image as opposed to altering the size here.