After a quick glance, they load the page in an iFrame and inject their CSS + JS into it. Any of changes you make will be "compiled" into a JS file which you th

After a quick glance, they load the page in an iFrame and inject their CSS + JS into it. Any of changes you make will be "compiled" into a JS file which you then include on your page. Whatever edits you made will only be reflected client side on load. Generating a screenshot is a completely different process than editing a website so I'm not sure Optimizely's tech is that useful to you.