When producing materials for end-users, try to include a screenshot of the “whole machine experience”, i.e. a screenshot of the feature you have in mind displayed on a real laptop or other screen. You can reinforce that with more detailed shots of the specific feature.
For developers, you should remove as much of the non-relevant content from the screenshot as possible, including (for example) window decoration and wallpapers, to focus attention on the specific element being discussed.
Screenshot styling for end users
For End Users show a feature screen shot in-situ supported by multiple standard screenshots in order to aid understanding of the software.
Screenshots for a mix of end users and developers
Use strategic standard screenshots to support your message.
Screenshots for developers
Use screenshots that show detail relevant to your copy. The developer audience is more interested in content and functionality, rather than the user interface styling.