I have a slight lack of clarity in your question, but as I can understand it, you're trying to open the file in a small window like it does on the mathworks site page. This is done using HTML iframes and it is basically opening that document in matlab online on a small iframe in your window.
An iframe basically opens a new page as a different window on your current browser tab/window itself.
So doing this is difficult but you can just open your file in matlab online on a different tab and that should work normally as expected.
Hope this helps.