XYplorer Beta Club

I tick this option and expect that for very small images (i.e: icons.png), the thumbnail will be enlarged so that they're comfortablely previewed. But no, nothing happens. So,
1) What is meant by the help file "Images that are smaller than the screen area are zoomed to fill up the space available"?
2) If there's no such enlarge option, then this is my wish. Bowsing through hundreds of icons without proper zoom-in is difficult.

You confuse "zoom to fill" with "zoom to fit". The latter is not available for thumbnails. So, yes, this makes it a wish.