"Selection: When you take a screenshot of only a
section of your screen the screen will dim and an instructional
window will appear telling you the steps you need to perform.
"Full Screen: The full screen screenshot will not include
Shutter in the picture.
"Window: A hand cursor will appear for you to click on the
window you want to take the screenshot of. For the most part
Shutter works exactly as you would expect. There are some features
that you might not be aware of. For example, Shutter has a set of
plugins to take advantage of. To use the plugins click on the
Screenshot menu and select the Execute a Plugin entry. This will
open a new window allowing you to select a plugin to use. Say, for
example, you wanted to add a watermark to your screenshot. You can
do this by first taking the screenshot, and then opening the
Plugins window and selecting the Watermark plugin. You can then be
specific about what you want your watermark to say, where you want
it, and what font size you want to use."