"manifest_version": 2,
 "name": "test extension",
 "version": "1.0",

 "web_accessible_resources": [
   "image.png"
 ],

 "content_scripts": [
   {
     "matches": [ "http://example.org/" ],
     "js": [ "RenderImage.js" ]
   }
 ]

I'm trying to create an extension that has a menu-like feature, with a "drop-down", which shows more alternatives, however, when I tried to import the image, it didn't work. So I created a "test extension" in which I tried again, in a much more simplified enviroment. However, I don't seem to get this to work (I have included the image in "web_accessible_resources" and used the browser.extension.getURL("image.png"); but It doesn't work), am I doing something wrong, and if so, how are you supposed to do in order to implement images on extensions? (RenderImage.js): _________________ document.body.style.backgroundImage = browser.extension.getURL("image.png"); _________________ (manifest.json): __________________ { "manifest_version": 2, "name": "test extension", "version": "1.0", "web_accessible_resources": [ "image.png" ], "content_scripts": [ { "matches": [ "http://example.org/" ], "js": [ "RenderImage.js" ] } ] } ____________________ (I loaded the extension in the temporary load on about:debugging)