your avatar is not 100x100, its 44x52, which means about half the size you could have it.
Just to nitpick, 44x52 is actually a lot closer to a quarter of the size of 100x100 than half. 
(22.88% for those who really want to be pedantic.)
I assume you meant half in each dimension. 
brilliant, yet dumb. ppl can only take your word on that you have an avatar. if there were some other way of verification, then maybe.
I did say right click, did I not? If you right click and view the image on someone else's avatar, you can see their avatar. If you right click and view image on my avatar, you can see that it is indeed present (here). If, by contrast, you right click and view image on someone's avatar who does not have an avatar, you'll get this gem (or an equivalent).
Ah, I see! It is brilliant! Brilliant I say! You made your avatar the "No avatar" icon! Now, even though it looks like you have no avatar you really do! Brilliant!

Thank you.
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Also, for what it's worth-my "avatar" looks like shit when blown up, so I probably won't bother resizing it.