The communication icons displayed depend on the types of information you have saved for individual contacts.
Tap a contact to view the entry details (from Contacts, Favorites, Groups, or Recent).
Tap the icon corresponding to the type of communication you want to start.
The Dial icon places a call to the number.
The Message icon starts a message.
The Mail icon starts an email.
You can also tap the contact's picture on the left side of the entry to display the Quick Contact icons.