Template overrides are a way of changing the way Joomla shows something without changing the extensions or core Joomla system. That's important because it means that as Joomla and/or extension is upgraded to new versions you will not have to repeat all the changes you made.
MijoVideos strictly uses the Joomla's override system and comes with 3 overrides by default in addition to the default one; YouTube, Vimeo and Dailymotion. So you can set the view of MijoVideos just like these popular sites.