I will create a dynamic page with content added and rearranged by JavaScript. Is it possible to create a jpg image of this content? - let's say, everything that is inside the container div will be generated to an image. If so, could anyone give me some good tips of this technique?
The traditional method is to run a "headless browser" on your server, "browse" to that url, and take a screenshot. It can be done to some accuracy on the client side in HTML5 browser, see this discussion:
This question may help: Using HTML5/Canvas/JavaScript to take screenshots
and then this one: convert canvas to jpeg image
The sequence of your algorithm would be something like: