Thumbnail option is greyed out on the view menu

I have recently installed SmartFTP. I am connecting to a FTP server that I manage. When I attempt to set the view menu to show thumbnails for the jpg images on the server that option is greyed out. What do I need to do on the server or on the client to view thumbnails of the images in SmartFTP?

Think about it: It's not (easily) possible to display thumbnails of images on a remote server. That's why the option is grayed out, it's not available for remote sites.