I love this subtle micro-interaction using GSAP where you hover over the play icon to show a little animation and on click, the play icon transforms into a youtube video. It was designed by Maciej Leszczyński.
Here is another similar snippet with a play button to Video Animation
If you are having trouble with the pen, try the archived copy on GitHub
Icon to Video Snippet
See the Pen Morph Play Button To Video Player #GSAP #ExpoScaleEase by Maciej Leszczyński (@asistapl) on CodePen.0