Why can't I send a picture from Gallery to facebook?

[AC Question]

It's a new phone and I've only taken a few pictures. When I open Gallery and tap on the picture I want to send to facebook, I see Favorite, Share, Edit, and Delete at the bottom of the picture. When I tap on Share, I see icons for AT&T Locker, Add a Pin, Add to OneNote, Android Beam, AT&T Mail, and Bluetooth, but nothing for facebook. I have been on facebook for years and view it daily.