Many probably noticed how simple the GTK file picker is, there's some basic feature missing like the ability to manage files/folders (renaming, deleting etc) and the one deal breaker for me: proper thumbnails. Now to avoid common misunderstanding, I know that the dialog does provide a thumbnail, but ONLY when you select a file, like this:

What I meant by proper thumbnail is:

My question is: is there any way to use an alternative? Though I don't even know if there's one out there

I do know that there's an option in about:config to enable/disable it but to be honest, the one that ships with Pale Moon is no better, worse even.