demo HTML page to show options for mouse hover pop-up window

I need a single web page (HTML file) developed to show me all the options I would have available for specifying to my website designer how to do a pop-up of an image when the user hovers their mouse over a link or image (I want this functionality on my home page to show a 10-second animated GIF of how something works). I don’t know if an image can be opened with a CSS Tooltip or if it requires some other technique, or even JavaScript. I could read about the tooltip HTML/CSS mechanism online somewhere and learn the options, but would rather just have someone do it in a way that I could test all the options. What variations can be done with it? What size can it be? Can it be placed somewhere specific in the window? Can it have a border? Can it be an animated GIF or not? For any options that are possible, I’d like this demo file you create to be structured so that I can make a copy of it and change the settings of variables at the top of the file that will control all the controllable aspects of the pop-up. E.g., the file might start with these lines: window_W = 600; window_H = 800; window_border_pixels = 6; window_border_color = aqua; image_location = ../images/[login to view URL] window_location = "tbd"; others? So this tiny job requires you not only to code the file for me but to ensure that you expose all the options I might have available in doing such a mouse hover pop-up.