Cool demo that uses clip-path: path(…);, a feature that recently shipped with Chromium, making it supported in all three major rendering engines.
See the Pen About Us Pop-Out Effect by Mikael Ainalem (@ainalem) on CodePen.
Peeking under the hood – using the SVG Path Visualizer — you can see that it’s the .container-inner that is clipped not in a circular way, but a vertical rectangle with a circular bottom. The photo of the person itself already is transparent and using scale and translate the pop-out effect is created.