Zoom in transition to second image on portfolio items

Hi, I saw a cool effect that zoom transitions to a second image on portfolio items on the following website: https://www.mikekus.com/

What would be the code to recreate this effect?

Thanks a lot in advance!

You mean hover on each image > Show another image

or

Hover on each image >> Show another image + text?

And which page (your site) you want to apply this effect?