If you template has a Presentation-item configured (see feature Separate Presentation Settings from real Content) then it means that your content-item can have special design-rules to display it here.
To understand the example, let's assume you have simple content, and sometimes the title should be blue, magenta or green. This information doesn't really go with the simple-content, because if you re-use this content elsewhere, it may need other presentation-settings there. So in this example, your Presentation-Item has the following fields:
The token would then be
And a simple use case would be (see also in the Demo-App the simple example with Presentation)
<h3 style="color: [Content:Presentation:Color]">[Content:Title]</h3>