This panel allows you to refine your filter by hiding categories of File Types, such as all Graphics Files i.e. if you un-tick the Graphics Files option, any image resources in the current folder will be hidden in the Resource pane:

If you don’t want to hide all images in a folder but only ones of certain type, for example JPEG files, you could un-tick the JPEG option from the File Types List.

By default, all options are ticked.