The Windows version of Snagit allows you to right-click on the images tray and close all open images at once. Snagit for Mac lacks this option. I use it a lot on Windows and would love to see it added to the Mac version,
For any Windows users that read this, it's not exactly that simple. You cannot right-click anywhere on the Recents tray. I really wish you could. It requires right-clicking very near the bottom of the application. Kind of below the thumbails where the scroll bar would appear.