Keep and remove differences

If your theme (or possibly another plugin) has some code set up so if you click on a gallery image it pops it open in a lightbox, that’s not necessarily ideal (or functional) if you’re trying to, say, link the image to another site or another page. So the “Remove” setting is on by default under the assumption most people will be linking to other pages or sites with their custom links.

Marking as resolved due to no further response from original poster.