Previewing images

I love fman and would love to have it as my default file system. I only have 1 (major?) concern / struggle I need help with. I work a lot with images and previewing them can be a pain. For example, if I have a folder with screenshots I need to either preview 1 at a time in "Preview" (Osx) or open a selection. This is problematic cause everytime I need to look at an image I need to open it in a external program and in my case (Osx) it launches finder which then must be closed. In Finder for example, you can hit spacebar to quickly view an image without opening it—you can also use the small thumbnails for reference.

So what is the solution? Implement an option to be able to display small thumbnails for each image in fman? I just want to be able to navigate through my huge folders of pictures and have some type of idea where I am without having to open every image everytime to get an idea.

Hopefully it makes sense, super grateful for any advice since I almost entirely rely on fman these days! Only using Finder when forced to etc. (Would also be amazing if this feature would work on Win aswell since Im using both systems ( Osx / WIn )

No files, tests, or entry points are named in the issue. Start by locating the image-preview and file-list UI, then define thumbnail behavior for macOS and Windows; done means images can be browsed in large folders without opening an external program.