You get the script code, copy it to footer of your web page, and you can start playing interactive media ads within your videos & images.
You can see it in action here : http://keepdsmile.com/publitio/espreso.php
Wrapper basically fetches targeted videos & images and turns them into interactive media (video) elements, that can have both pre-roll and overly ads within them.
Publishers are seeing amazingly high RPM (CPM) rates within ads networks thanks to this monetization solution.
If you have a website with a decent traffic and rich-in media (video & images) content, this solution can empower your media and bring additional revenue stream to you.
You can start testing Wrappers by creating free account and by visiting https://publit.io/dashboard/wrapper
Off course, you will need your own VAST or Goolge Adsense for video adtag, which you can get directly via DFP, ADX/Google Adsense (if your sites meets their traffic criteria) or some Adsense Partners programs (that take their cut):
And here are examples how Publitio Media Player looks like - one with preroll and other with overlay ad: