If you just need to get All images from the site you first need to get all tags and than get all background images from css that is loaded on this site. But still this can be not all images because some can be loaded by javascript(or some tags or css can be changed with javascript).
To make sure you get everything you need to completely load the website as the browser loads it, get the DOM tree, iterate over it, check css properties in each element in the DOM for background images, and also extract all images from tags.
I am not sure if Jsoup can do this. Probably it will not take in account javascript and maybe even css. It seems to be just html parser.
I think the best way is to use developer console of a browser(sending back to my answer to your previous question). From the console you can execute javascript for iterating over all elements in the DOM tree and get a list of urls that you can later copy and use for loading images by some server side script.