Screen shot button within the status bar
This feature concerns
Who will use the new feature? A basic user would like this new feature, cause it's very simple to proceed.
What is the target of the new feature for this user?
Simplicity and time saving
Why this user would like to use this feature?
Cause it's simple and might be intuitive. It would save pressing power button to create screen shot.
To make a screen shot a user would need to open a status bar and tap on a new icon Screenshot :-)
the same as in the Examples section