I changed my Gravatar the other day but I had forgotten the e-mail I was changing it on was linked to StackOverflow. So this resulted in my SO Gravatar being changed (to a picture of my foot with a frowny face, circa 2003).
I didn't want this image associated with my SE accounts and instead of changing my e-mail, I decided to take the lazy option and upload an image to use as my Avatar with the new(ish) feature.
I am pretty sure I changed the avatar via my SO Profile and the change seems to have been applied to my SE Network profile also.
However if you take a look at my SO.Meta Profile or Workplace Profile you can see they are displaying the Gravatar associated with my e-mail instead.