Fokti can be tricky to figure out!
If you havent already changed the setting to allow for comments, here is what you need to do:
1) Hover the mouse around your name (on the left hand side of the screen)
2) Go to My Settings
3) On the right hand side, under Account Settings, click on Change Albums
4) There are different choices, including Posting Comments allowed for: You can select Anybody, Fokti Members Only, My Fokti Friends Only, Myself