I'm assuming you mean the text above the image, right? Where it says "Mom to THREE mutts!" on mine?

Well.. if that IS what you're talking about...
This is how you put the text.


Go to your user CP
Click on Edit Profile.
Scroll down until you see:

Or something similar. Type what text you want into the text field. Scroll down and click on submit modifications.




Either that, or do you mean pictures on the actual avartar (Like mine says " I LOVE Mutts!" -- For that you need a picture editing program.