No real special meaning, just a combination of two things:
1) I am a HUGE fan of Seth MacFarlane - he is a GENIUS!
2) I actually look like Steve Smith (especially in the episode where he grew breasts)
I cropped a screencap I made from a DVD and I'm very pleased at how well it turned out. Although I am worried I'll have to change it - there are regulations about images of minors and the character of Steve Smith is only 12-13. Then again, I have seen some Stewie Griffin avatars so maybe the regulation doesn't apply to cartoons. I haven't had any complaints.