Oh wow, looks like a new feature.

The "page" links in a stylesheet with the address "resource://gre/res/TopLevelImageDocument.css". If you remove that reference, then the image displays in the old style.

Edit: Please skip the rest of this post and check out the next one.

There might be a more elegant solution than that, but you could use a bookmarklet to strip out that link when you want to view the page in its old style. A bookmarklet is a snippet of JavaScript you save on the Bookmarks toolbar for quick access.

First, copy the following code to the clipboard (it's all one long line):

javascript:var ssheet=document.querySelector('link[href="resource://gre/res/TopLevelImageDocument.css"]'); if(ssheet)ssheet.parentNode.removeChild(ssheet); void 0;

Next, if you are not displaying the Bookmarks Toolbar, use View > Toolbars > Bookmarks Toolbar to display it. (If you aren't using the classic Menu bar, press Alt+v to call up the old View menu. Right-clicking the gray area just below the page address also allows you to display the Bookmarks Toolbar.)

Right-click on the Bookmarks Toolbar (or Mac equivalent of right-click!) and choose New Bookmark.

Paste the code into the Location box (the second box).

Then type a useful name in the Name box (e.g., Oldstyle Picture) and click Add.

Now, when you want to tweak the image display, click the button to run the script.

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Manual clicking is a hassle, so it might make sense to look into other solutions. (Greasemonkey didn't seem to work; I think it might not run on .jpg files.)

You can look at this extension.

• Old Default Image Style: https://addons.mozilla.org/firefox/addon/old-default-image-style/

See also this forum thread for a solution with userContent.css:

• [/questions/923127]

• http://forums.mozillazine.org/viewtopic.php?f=38&t=2443535