The second line below ur avatar is like a small few word bio that can be changed, if u go to the user control panel and click on edit profile. Then u scroll down to...custom text?? Or custom user text?? (something like that) where u edit what it says. You can change it to whatever you want - with a few exceptions obviously. Its not based on how many posts uve made. Look at mine...
Oh and subscriber just states that you have a VIP membership!
The bold line cant be changed tho!