You don't have to use the mouse for this application, a lot of items can be handled by the keyboard. Hold down command to see some keyboard shortcuts. In addition to the ones shown, you can use the space bar or right arrow to press the default button and you can press the 'O' key to view the image full screen. The delete key will move the current file to the Trash and continue with the next file in the list. The behaviour of the other items is beyond my control, I have put in a few Plug-Ins that I found for this example.
Most items are self explanatory.
The Create preview item creates a QuickTime compressed preview picture that will show up in open dialogs in any application that has the ability to show these. Still on the list of things to be fixed. All item creates a full screen image of all files in the current run, however it will only be in the menu if there are more than 1 files in the current run. This will take some time to create, one by one the images will come in. When it's done, or you cancelled, you can choose from the menu that comes up when the mouse is pressed.