Haven't changed my avatar since I joined in 2012-- it's Boris Aronson's gorgeous sketch of the tree in PACIFIC OVERTURES to match my name. Suddenly last week some stranger showed up in its place. How can I get my original one back? (Asked by a technologically challenged luddite.)
Same thing happened to me (I actually haven't changed it back because I don't mind the new photo).
I asked the Mods and they said it was because of a change in the server, and so some photos might have changed if the file has the exact same name (which is why your new photo is of someone in a tree, and mine is still related to Sunday in the Park With George)
We recently updated our server moving to a different provider. In the transfer, it is possible that if multiple people had uploaded different images with the same file name, they might not have been put back in the same spot.
However, you are welcome to reupload the original version. We apologize about the confusion, this was not something that we anticipated could potentially happen.