Gravatar will assign a unique symmetrical pattern to you. And it will always be your pattern.
The point of gravatar is that if ten sites support it, and you upload a real picture there to be your avatar, then all ten sites that you use will show your new picture... you didn't have to update them individually.
But if you haven't yet uploaded a picture to gravatar, then it uses a hash of your email address to generate a unique one for you.
Er, it doesn't work like that.
Gravatar will assign a unique symmetrical pattern to you. And it will always be your pattern.
The point of gravatar is that if ten sites support it, and you upload a real picture there to be your avatar, then all ten sites that you use will show your new picture... you didn't have to update them individually.
But if you haven't yet uploaded a picture to gravatar, then it uses a hash of your email address to generate a unique one for you.