The Resource pane appears on the right-had side of the Resource Manager window and shows the resources contained in folder selected in the Organiser:

By default, the resources are listed by the Filename column in ascending order (i.e. from A to Z). Click on a column heading if you want to sort by that column. Click on the icon in the column heading if you want to change the display order from ascending to descending order (i.e. from Z to A).