Since a lot of people will come to the comments without reading the article itself:
It is embedding the Youtube video, like a lot of websites and apps do - if you ever watched a youtube video outside of youtube.com or official apps, odds are it is using the same API as that app.
It still shows ads and uses the Youtube website directly for certain parts, but with some custom CSS and JS akin to how browser extensions would work.
Since a lot of people will come to the comments without reading the article itself:
It is embedding the Youtube video, like a lot of websites and apps do - if you ever watched a youtube video outside of youtube.com or official apps, odds are it is using the same API as that app.
It still shows ads and uses the Youtube website directly for certain parts, but with some custom CSS and JS akin to how browser extensions would work.