Image dimensions before title. Thread: https://stackoverflow.com/questions/32949162/can-firefox-show-resolution-of-image-before-name-in-tab-title

image-dimensions-before-title-MutationObserver.user.js

// ==UserScript==
// @name            Image dimensions before title
// @description     Request by supasd. Code by wOxxOm. https://stackoverflow.com/a/32949363/5382305
// @icon            https://assets-cdn.github.com/images/icons/emoji/unicode/1f504.png
// @grant           none
// @run-at          document-start
// ==/UserScript==

if (!changeTitle()) {
    new MutationObserver(function(mutations) {
        var nodes = mutations[0].addedNodes;
        if (nodes[0] && nodes[0].localName == 'title' && changeTitle(nodes[0])
        || document.body && document.body.children.length) {
            this.disconnect();
        }
    }).observe(document, {subtree: true, childList: true});
}
document.addEventListener('DOMContentLoaded', changeTitle);

function changeTitle(node) {
    var m = document.title
                    .match(/^(.+?\.\w+) \((?:([^,]+?), )?(\d+)\s*[x×]\s*(\d+)( \w+)?\)/);
    if (m) {
        document.title = m[3] + 'x' + m[4] + ' ' + m[1] + (m[2] ? ' (' + m[2] + ')' : '');
        return true;
    }
}

image-dimensions-before-title-simple.user.js

// ==UserScript==
// @name            Image dimensions before title
// @description     Request by supasd. Code by wOxxOm. https://stackoverflow.com/a/32949363/5382305
// @icon            https://assets-cdn.github.com/images/icons/emoji/unicode/1f504.png
// @grant           none
// ==/UserScript==

(function() {
    var m = document.title
                    .match(/^(.+?\.\w+) \((?:([^,]+?), )?(\d+)\s*[x×]\s*(\d+)( .+?)?\)/);
    if (m)
        document.title = m[3] + 'x' + m[4] + ' ' + m[1] + (m[2] ? ' (' + m[2] + ')' : '');
})();

Reproducible every single time (on Windows 8.1):
Firefox Nightly (44):
Greasemonkey 3.4.1:

Using Firefox Nightly (44) or Firefox Developer Edition (43) produces the same results.
Though in Firefox Nightly (44) using Greasemonkey 3.4.1, in step 3., clicking 'Use Script From Clipboard' adds the userscript right away. No Scratchpad window pops up, so no need to click 'Save' and close Scratchpad window. Trying to edit the userscript by clicking 'Options' - 'Edit This User Script' does nothing - the userscript can't be edited. 

Firefox Nightly (44):
Greasemonkey 3.5beta3:

Using Greasemonkey 3.5beta3 or 3.4.1 produces the same results on Firefox Nightly (44).
Though in Firefox Nightly (44) using Greasemonkey 3.5beta3 - yeah well it works the same as in Firefox Developer Edition (43). It's just that using Firefox Nightly (44) with Greasemonkey 3.4.1 doesn'tt as noted above.