Zoom

I've seen in some templates there's a simple magnifying zoom on images embedded in files/posts. I also read it is/was out of the box in the Blog template but can't seem to find it. How is that accomplished? For reference see images this provided example site: https://benlog.net/

I love the smooth, build-in image zoom (Blog Template), but I have a situation (image in a teaser section on the start page) where I would like to selectively turn it off, because it is preventing the image from being clickable. Is this possible somehow?