We strongly suggest you add a photo to your profile. It gives your posts a unique attachment and helps others quickly identify you from everyone else. Who wants to look at a faceless face, after all?
Here are the steps to adding a profile photo:
1) Click your name, in the upper right-hand corner (you'll see a "white arrow" pointing down).
2) Click "My Profile"
3) In the upper right, below the black header, you'll see the "Edit my Profile" black button - click it
4) Add your photo through the top menu item: "Photo"