There are a number fo ways that something like this can be designed. It's likely that the main SWF is loading either other SWFs or bitmaps at runtime to populate the different slides. It could be a move clip that's pre-set up and populated with the remotely loaded content at runtime. Often a plain text or XML file is updated to tell the main swf what items to load and from where. The SWF loads the text or XML file and them loads the items according to the XML file contents. It could be done lots of different ways, but this is a best guess.