When previews are enabled, the Special menu lets you share photos, music, videos, and documents to applications, social media accounts, and other services.
Select the file in the Special menu and choose a service from the Share submenu. The displayed options - Mail, Messages, AirDrop, Notes, Twitter, Facebook, and others - depend on the type of file you want to share.
Provide any additional information needed for the chosen sharing method. For example, if you are sharing a photo using Twitter, type some text describing the photo.