Each client will display a different type of default profile image for those who have not yet added one. Some clients, such as Amethyst, use those robots by default.
Discussion
Thanks. Gathered that from an earlier answer, but was unsuccessful finding documentation on it. It’s not a big deal, just curious to learn more about images tied to word/strings, in the event that’s what is going on with those (haven’t researched samurai’s robot thing at all really, and not sure if related)