click_to_show.tamper.js

// ==UserScript==
// @name       Hipchat Click to View Images
// @version    0.1
// @match      https://*.hipchat.com/chat
// @copyright  2014, Zach "theY4Kman" Kanzler
// @grant      GM_unsafeWindow
// ==/UserScript==


// Add styles to initially disable images
unsafeWindow.$('head').append([
    '<style type="text/css">',
    '.preview .image a {',
    '  display: none;',
    '}',
    '.preview .image:before {',
    '  content: "Image hidden. Click to show.";',
    '  font-style: italic;',
    '  color: grey;',
    '  cursor: pointer;',
	'}',
    '.preview.shown .image a {',
    '  display: block;',
    '}',
    '.preview.shown .image:before {',
    '  content: "";',
	'}',
    '</style>'
].join('\n'));


unsafeWindow.$(document).on('click', '.preview:not(.shown) .image', function() {
    $(this).parent().addClass('shown');
});