As far as I know, you can use only actual images/URLs to images as sources for the image-attribute. Is there a way to circumvent this restriction and use the icons of a font like the one stated above? Currently using Genero 2.5.
Genero 3.00 released in December 2015 introduced the ability to use true type fonts as images. http://4js.com/online_documentation/fjs-fgl-manual-html/#fgl-topics/c_fgl_images_resource_spec.html
This example https://github.com/FourjsGenero/ex_fontawesome_viewer illustrates the use.