Expand image on click

Very cool example.

Only by custom code and some AJAX for page transitions. In your example i think this is custom code but maybe try barba.js:

http://barbajs.org/demo/grid/index.html

How to? by searching for webflow freeancer with Javascript background -or- by learning barba.js (forum Q about this):

Anyway, no way to answer “how to do this” by forum Q.